SERA Sera Prognostics Inc

As Filed Pursuant to Rule 424(b)(5)
Registration No. 333-281347

PROSPECTUS SUPPLEMENT

(To Prospectus dated August 13, 2024)

Up to $50,000,000

Sera Prognostics, Inc.

Class A Common Stock

We have entered into an at-the-market sales agreement with TD Securities (USA) LLC, or TD Cowen, as our sales agent, relating to the shares of our Class A common stock offered by this prospectus. In accordance with the terms of the sales agreement, we may offer and sell shares of our Class A common stock having an aggregate offering price of up to $50,000,000 from time to time through or to TD Cowen, as sales agent or as principal.

Our Class A common stock is listed on The Nasdaq Global Market, under the symbol “SERA.” On August 6, 2024, the last reported sale price of our Class A common stock was $7.41 per share.

Sales of our Class A common stock, if any, under this prospectus supplement will be made in sales deemed to be “at the market offerings” as defined in Rule 415 promulgated under the Securities Act of 1933, as amended, or the Securities Act. TD Cowen is not required to sell any specific amount of securities, but will act as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed terms between TD Cowen and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

The compensation to TD Cowen for sales of Class A common stock sold pursuant to the sales agreement will be an amount equal to an aggregate of 3.0% of the gross proceeds of any shares of Class A common stock sold under the sales agreement. In connection with the sale of the Class A common stock on our behalf, TD Cowen will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of TD Cowen will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to TD Cowen with respect to certain liabilities, including liabilities under the Securities Act or the Securities Exchange Act of 1934, as amended, or the Exchange Act.

Our business and an investment in our Class A common stock involve significant risks. These risks are described under the caption “Risk Factors” beginning on page S-7 of this prospectus supplement and in the documents incorporated by reference into this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus supplement. Any representation to the contrary is a criminal offense.

TD Cowen

The date of this prospectus supplement is August 13, 2024

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement is part of a shelf registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or the SEC, using a shelf registration process. Under the base prospectus included in the shelf registration statement, we may offer securities having an aggregate offering price of up to $100,000,000. Under this prospectus supplement and the accompanying prospectus, we may offer shares of our Class A common stock having an aggregate offering price of up to $50,000,000 from time to time at prices and on terms to be determined by market conditions at the time of offering. The $50,000,000 of shares of our Class A common stock that may be sold under this prospectus supplement are included in the $100,000,000 of securities that may be sold under the registration statement.

If the information contained in this prospectus supplement differs or varies from the information contained in any document incorporated by reference herein that was filed with the SEC before the date of this prospectus supplement, you should rely on the information set forth in this prospectus supplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date (for example, a subsequently filed document deemed incorporated by reference in this prospectus supplement), the statement in the document having the later date modifies or supersedes the earlier statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

You should rely only on the information contained or incorporated by reference in this prospectus supplement. We have not, and TD Cowen has not, authorized anyone to provide you with information that is in addition to or different from that contained or incorporated by reference in this prospectus supplement or contained in any permitted free writing prospectuses we have authorized for use in connection with this offering. We and TD Cowen take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may provide.

The information contained in this prospectus supplement and the documents incorporated by reference herein is accurate only as of their respective dates, regardless of the time of delivery of any such document or the time of any sale of our shares of Class A common stock. Our business, financial condition, results of operations and prospects may have changed since those dates. It is important for you to read and consider all information contained or incorporated by reference in this prospectus supplement in making your investment decision. You should read this prospectus supplement, as well as the documents incorporated by reference herein, the additional information described under the section titled “Where You Can Find More Information” and “Incorporation of Documents by Reference” in this prospectus supplement and any free writing prospectus that we have authorized for use in connection with this offering, before investing in our shares of Class A common stock.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in this prospectus supplement were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

As used in this prospectus supplement, “Sera,” the “Company,” “we,” “our” or “us” refers to Sera Prognostics, Inc. and its subsidiaries. References to our “Class A common stock” refer to the Class A common stock of Sera Prognostics, Inc.

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PROSPECTUS SUPPLEMENT SUMMARY

The following is a summary of what we believe to be the most important aspects of our business and the offering of our securities under this prospectus supplement. We urge you to read this entire prospectus supplement, including the more detailed consolidated financial statements, notes to the consolidated financial statements and other information incorporated by reference from our other filings with the SEC. Investing in our securities involves risks. Therefore, carefully consider the risk factors set forth in our most recent annual and quarterly filings with the SEC, as well as other information in this prospectus supplement and the documents incorporated by reference herein or therein, before purchasing our securities. Each of the risk factors could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our securities.

Overview of Sera

We are a women’s health company utilizing our proprietary proteomics and bioinformatics platform, and significant data resources, to improve maternal and neonatal health by discovering, developing, and commercializing blood-based biomarker tests and predictive analytic products and services. Our vision is to deliver pivotal and actionable information to pregnant women, their physicians, and health care payers to significantly enhance a mother’s pregnancy journey, improve maternal and neonatal health, and dramatically reduce health care costs. We believe that our method of combining the disciplines of proteomics and bioinformatics with rigorous clinical testing, data, and economic analysis enables us to provide physicians and expectant mothers with personally insightful, clinically meaningful, and economically impactful information designed to improve the pregnancy experience and outcomes for mothers and babies.

There are approximately 140 million births globally each year, and approximately 3.7 million births annually in the United States. Of these, it is estimated that as many as 30% are affected by various complications (i.e., a high-risk pregnancy), including: preterm birth, preeclampsia, fetal growth restriction, stillbirth, hypertension of pregnancy, gestational diabetes, and others. In many cases these complications have profound short- and long-term health consequences for the mother and baby. These health consequences of preterm birth alone are estimated to be approximately $25 billion annually in the United States. This underscores that existing methods to predict adverse pregnancy outcomes are insufficient for timely and effective proactive management for the vast majority of high-risk pregnancies. We believe that positive patient outcomes are the result of appropriate care, and the primary differentiator of patient care should be based on a determination of risk informed by a number of factors including our novel diagnostic tests.

Our first commercial product, the PreTRM test, is the only broadly validated, commercially available blood-based biomarker test to accurately predict the risk of a premature delivery, also known as preterm birth. The PreTRM test is a non-invasive blood test given to a pregnant woman, carrying a single fetus, during weeks 18 through 20 of gestation that provides an accurate prediction of the expectant mother’s risk of delivering spontaneously before 37 weeks’ gestation. Our commercialization strategy includes conducting clinical trials to demonstrate the health and economic benefits of early and accurate detection of preterm birth risk coupled with well-recognized interventions in higher risk patients, illustrating these benefits to healthcare providers and insurance payers, and providing convenient access to the test through streamlined specimen collection options. Beyond demonstration of efficacy, we look forward to studying the effectiveness and implementation of the PreTRM test in a real-world setting. Clinical trials conducted to date include the Prediction and Prevention of Preterm Birth, or the PREVENT-PTB Study, Serum Assessment of Preterm Birth Outcomes Compared to Historical Controls study, or the AVERT PRETERM TRIAL, and the Prematurity Risk Assessment Combined With Clinical Interventions for Improving Neonatal outcoMEs study, or the PRIME study. Manuscript results of these studies demonstrate consistency in the reported beneficial impact of the PreTRM test-and-treat strategy. Specifically, this includes evidence of a prolongation of gestation, shortened hospital or neonatal intensive care unit, or NICU, length of stay, and improvements in measures of neonatal morbidity/mortality. Our studies demonstrate a model indicating that by identifying and intervening in at-risk pregnancies, not identifiable by

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other approaches, babies destined for premature delivery remain in utero longer. This prolongation of gestation in the preterm period leads to more mature babies that require shorter hospital/NICU stays due to improved neonatal health. The PRIME study, for which enrollment was stopped due to efficacy at the interim analysis and is being prepared for publication, includes the same Primary and Secondary outcomes as the AVERT PRETERM TRIAL and affords the continued assessment of this model.

We believe market adoption by both health care providers and payers should be aided by the publications of our PREVENT-PTB study sub-analysis and the peer-reviewed positive data from our AVERT PRETERM TRIAL, as well as upcoming publications, including the results of our PRIME study and other real-world evidence studies. We believe the data that will be published in coming years, together with our current body of evidence, will further demonstrate the clinical and economic utility of our test.

In December 2023, we announced that the Data Safety Monitoring Board, or DSMB, overseeing our PRIME study recommended stopping enrollment due to efficacy, reporting that either co-primary endpoints, neonatal hospital length of stay and composite neonatal morbidity and mortality, met the stopping criteria for statistical significance at the pre-planned interim analysis. We adopted the DSMB’s recommendation and stopped PRIME study enrollment to focus on analyzing and reporting the available data. In May 2024, deliveries of all PRIME study participants were complete, inclusive of the approximately 2,000 remaining participants who were enrolled but had not delivered before enrollment was stopped in December 2023 per DSMB recommendation. All mothers and babies within the study have left the hospital and data monitoring for the final PRIME dataset is in progress. Manuscripts reporting study results, including top-line and exploratory analyses, are being prepared for submission and peer review after final analysis expected in fall 2024.

We have built an advanced, proprietary, and scalable proteomics and bioinformatics platform to characterize the biology of pregnancy and to discover and validate key protein biomarkers found in blood that are highly accurate predictors of dynamic changes that occur during pregnancy. By incorporating our proprietary technology platform into our rigorous data-driven development process, we have created a differentiated approach for effectively addressing major milestones, conditions, and features of pregnancy. We believe our large and growing pregnancy dataset (clinical, demographic, proteomic) is a substantial asset for understanding pregnancy complications, health inequities, and the personal pregnancy journey. We envision that our comprehensive approach will enable us to fully characterize one of the most important periods in the lives of women and their babies, and will help to improve their well-being.

We are actively discovering and developing several additional biomarker tests to predict other specific major conditions of pregnancy, such as a pregnancy risk prediction panel test. We believe these tests have the potential to offer significant health benefits to women and their babies. Among other products, we are developing a test designed to provide a more accurate estimate of the delivery date for expectant mothers for the purposes of planning maternity leave, required support, travel arrangements, and related considerations.

We have taken steps to significantly reduce our annual operating expenses across all aspects of our business and we believe our cash runway is sufficient to enable us to operate into 2027 based on our existing operating plans. We will continue to evaluate the allocation of our resources as we focus our efforts to accelerate the market adoption of our PreTRM test and the development and launch of additional pipeline products and services. Our evidence portfolio continues to grow with the publication of the PREVENT-PTB study sub-analysis of the potential benefit of care coordination and low-dose aspirin paired with PreTRM test results.

We recently announced the publication of the positive results from the AVERT PRETERM TRIAL in Diagnostics, an international, peer-reviewed, open access journal on medical diagnosis. Diagnostics highlighted this study on the cover of the journal issue. Notable results indicated an 18% reduction in severe neonatal morbidity and mortality. Additionally, there was a 7-day reduction in the mean neonatal hospital length of stay among neonates with the longest stays. The trial also showed an increase in the average gestational age at birth before 32 weeks by 2.48 weeks. Furthermore, there was a 28-day reduction in the neonatal length of hospital stay for babies born before 32 weeks’ gestation, significantly reducing the time spent in the hospital for those at risk

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of the earliest delivery. Significant reductions in neonatal morbidity and mortality were also reported, as well as hospital and NICU lengths of stay, in the entire intent-to-treat population. The test-and-treat strategy was linked to decreased odds of preterm birth and spontaneous preterm birth at various gestational ages.

Our real-world evidence implementation programs, targeting to expand PreTRM clinical utility data and replicate randomized controlled trial evidence in the real world, have been developed for study launches anticipated in the second half of 2024 and in 2025.

We recently completed validation of certain whole-blood collection and whole-blood compatible testing technologies, and have begun marketing and processing whole-blood specimens. This evolution to whole-blood collection will remove laborious specimen processing steps such as centrifugation and enable in-office physician or at-home consumer collection channels. We believe that whole-blood collection technologies, paired with ambient specimen shipment approaches, may enable greater market penetration and an optimal customer experience, while also potentially lowering costs.

We will continue to opportunistically pursue contracts with private and governmental payers and health systems with new positive data from the PREVENT-PTB study, the AVERT PRETERM TRIAL, and the PRIME study, along with real-world evidence studies and other data we plan to generate, and we believe these efforts may eventually result in material revenues.

Corporate Information and History

Our corporate headquarters are located at 2749 East Parleys Way, Suite 200, Salt Lake City, Utah 84109, and our telephone number is (801) 990-0520. Our website address is https://www.seraprognostics.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.

Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and all amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, are available free of charge through the investor relations page of our website as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.

All brand names or trademarks appearing in this prospectus are the property of their respective holders. Use or display by us of other parties’ trademarks, or products in this prospectus is not intended to, and does not, imply a relationship with, or endorsements or sponsorship of, us by the trademark.

Implications of Being an Emerging Growth Company and a Smaller Reporting Company

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, as amended, or the JOBS Act. As an emerging growth company, we may take advantage of specified reduced disclosure and other requirements that are otherwise applicable generally to public companies. These provisions include:

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We may take advantage of these exemptions until the fifth anniversary of our initial public offering or such earlier time that we are no longer an emerging growth company. We would cease to be an emerging growth company on the date that is the earliest of (i) the last day of the fiscal year in which we have total annual gross revenue of $1.235 billion or more; (ii) December 31, 2026; (iii) the date on which we have issued more than $1.0 billion in nonconvertible debt during the previous three years; or (iv) the last day of the fiscal year in which we are deemed to be a large accelerated filer under the rules of the SEC, which means the market value of our common stock that is held by non-affiliates exceeds $700 million as of the prior June 30th. We may choose to take advantage of some but not all of these exemptions. We have taken advantage of reduced reporting requirements in this prospectus supplement. Accordingly, the information contained herein may be different from the information you receive from other public companies in which you hold stock. We are in the process of evaluating the benefits of relying on other exemptions and reduced reporting requirements under the JOBS Act. Subject to certain conditions, as an emerging growth company, we may rely on certain of these exemptions, including without limitation, providing an auditor’s attestation report on our system of internal controls over financial reporting pursuant to Section 404(b) of the Sarbanes-Oxley Act.

We are also a “smaller reporting company” as defined in the Exchange Act. We may continue to be a smaller reporting company even after we are no longer an emerging growth company. We may take advantage of certain of the scaled disclosures available to smaller reporting companies until the fiscal year following the determination that our voting and non-voting common stock held by non-affiliates is more than $250 million measured on the last business day of our second fiscal quarter, or our annual revenues are less than $100 million during the most recently completed fiscal year and our voting and non-voting common stock held by non-affiliates is more than $700 million measured on the last business day of our second fiscal quarter.

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RISK FACTORS

An investment in our Class A common stock involves a high degree of risk. Before deciding whether to invest in our Class A common stock, you should consider carefully the risks described below and discussed under the sections captioned “Risk Factors” contained in our most recent Annual Report on Form 10-K, as well as in any of our subsequent Quarterly Reports on Form 10-Q or our Current Reports on Form 8-K, which are incorporated by reference herein in their entirety, together with other information in this prospectus supplement, the accompanying prospectus, and the information and documents incorporated by reference in this prospectus supplement. If any of these risks actually occurs, our business, financial condition, results of operations or cash flow could be seriously harmed. This could cause the trading price of our Class A common stock to decline, resulting in a loss of all or part of your investment.

Risks Related to this Offering and Our Class A Common Stock

Our management will have broad discretion over the use of the net proceeds from this offering, and you may not agree with how we use the proceeds and the proceeds may not be invested successfully.

Our management will have broad discretion as to the use of the net proceeds from this offering and could use them for purposes other than those contemplated at the time of this offering. Accordingly, you are relying on the judgment of our management with regard to the use of these net proceeds, and you will not have the opportunity, as part of your investment decision, to assess whether the proceeds will be used appropriately. It is possible that the proceeds will be invested in a way that does not yield a favorable, or any, return for Sera.

If you purchase shares in this offering, you will suffer immediate and substantial dilution in the book value per share of the Class A common stock purchased in the offering.

If you purchase shares of our Class A common stock in this offering, you will incur immediate and substantial dilution in the as adjusted net tangible book value of your stock of $4.67 per share as of June 30, 2024, based on an assumed public offering price of $7.41 per share, which was the closing price of our Class A common stock on The Nasdaq Global Market on August 6, 2024, because the price that you pay will be substantially greater than the net tangible book value per share of the shares you acquire. You will experience additional dilution upon the exercise of options and warrants, vesting of restricted stock units, including those options, warrants and restricted stock units currently outstanding and those granted in the future, or the issuance of restricted stock or other equity awards under our stock incentive plans. See “Dilution” for a more detailed discussion of the dilution you will incur in connection with this offering. In addition, in the past, we have issued options to acquire Class A common stock at prices below the assumed public offering price of $7.41 per share, warrants to purchase Class A common stock at prices below the assumed public offering price of $7.41 per share, and have granted restricted stock units. To the extent these outstanding options and warrants are ultimately exercised or these restricted stock units vest, you will incur additional dilution.

You may experience future dilution as a result of future equity or convertible debt offerings.

In order to raise additional capital, we may in the future offer additional shares of Class A common stock or other securities convertible into or exchangeable for our shares of Class A common stock at prices that may not be the same as the prices per share in this offering. We may sell shares or other securities in any other offering at a price per share that is less than the price per share paid by investors in this offering, and investors purchasing shares or other securities in the future could have rights superior to existing stockholders. The price per share at which we sell additional shares of Class A common stock, or securities convertible or exchangeable into shares of Class A common stock, in future transactions may be higher or lower than the price per share paid by investors in this offering.

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The shares of our Class A common stock offered under this prospectus supplement may be sold in “at the market” offerings, and investors who buy shares at different times will likely pay different prices.

Investors who purchase shares under this prospectus supplement at different times will likely pay different prices, and so may experience different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices, and numbers of shares sold, and to determine the minimum sales price for shares sold. Investors may experience declines in the value of their shares as a result of share sales made in connection with “at the market” offerings at prices lower than the prices they paid.

The actual number of shares we will issue under the sales agreement, at any one time or in total, is uncertain.

Subject to certain limitations in the sales agreement and compliance with applicable law, we and our sales agent may mutually agree to sell shares of our Class A common stock under a transaction acceptance at any time throughout the term of the sales agreement. The number of shares that are sold by TD Cowen after agreement on the terms of the transaction will fluctuate based on the market price of the shares of our Class A common stock during the sales period and limits we set with our sales agent. Because the price per share of each share sold will fluctuate based on the market price of our shares of Class A common stock during the sales period, it is not possible to predict the number of shares that will ultimately be issued.

Because we do not anticipate paying any cash dividends on our capital stock in the foreseeable future, capital appreciation, if any, will be your sole source of gain.

We have never paid or declared any cash dividends on our capital stock. We currently intend to retain earnings, if any, to finance the growth and development of our business and we do not anticipate paying any cash dividends in the foreseeable future. As a result, it is likely that only appreciation of the price of our Class A common stock will provide a return to our stockholders.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, and the documents incorporated by reference herein or therein, contain forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended, that are intended to be covered by the “safe harbor” created by those sections. Forward-looking statements, which are based on certain assumptions and describe our future plans, strategies and expectations, can generally be identified by the use of forward-looking terms such as “believe,” “expect,” “may,” “will,” “would,” “should,” “could,” “seek,” “intend,” “plan,” “continue,” “estimate,” “anticipate” or other comparable terms. All statements other than statements of historical facts included in this prospectus supplement and the documents incorporated by reference herein or therein regarding our strategies, prospects, financial condition, operations, costs, plans and objectives are forward-looking statements. Examples of forward-looking statements include, among others, statements about:

We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important cautionary statements in this prospectus supplement, the accompanying prospectus and in the documents incorporated by reference in this prospectus supplement, particularly in the “Risk Factors” section, that we believe could cause actual results or events to differ materially from the forward-

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looking statements that we make. For a summary of such factors, please refer to the section entitled “Risk Factors” in this prospectus supplement, as updated and supplemented by the discussion of risks and uncertainties under “Risk Factors” contained in any supplements to this prospectus supplement and in our most recent Annual Report on Form 10-K, as revised or supplemented by our subsequent Quarterly Reports on Form 10-Q or our Current Reports on Form 8-K, as well as any amendments thereto, as filed with the SEC and which are incorporated herein by reference. The information contained in this document is believed to be current as of the date of this document. We do not intend to update any of the forward-looking statements after the date of this document to conform these statements to actual results or to changes in our expectations, except as required by law.

In light of these assumptions, risks and uncertainties, the results and events discussed in the forward-looking statements contained in this prospectus supplement or in any document incorporated herein by reference might not occur. Investors are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this prospectus supplement or the date of the document incorporated by reference in this prospectus supplement. We are not under any obligation, and we expressly disclaim any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise. All subsequent forward-looking statements attributable to us or to any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section.

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USE OF PROCEEDS

We may issue and sell shares of our Class A common stock having aggregate gross sale proceeds of up to $50,000,000 from time to time. Because there is no minimum offering amount required to be sold in connection with this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. We intend to use any net proceeds from the sale of Class A common stock under this prospectus supplement for our operations, the commercialization of the PreTRM test, and the further development and potential commercialization of any or all of our product candidates and future product candidates, and other general corporate purposes, including, but not limited to, working capital, intellectual property protection, investments, acquisitions and collaborations. The amounts and timing of our actual expenditures will depend on numerous factors, including those described under “Risk Factors” in this prospectus supplement and the documents incorporated by reference herein, as well as the amount of cash used in our operations. As a result, our management will have broad discretion to allocate the net proceeds, if any, we receive in connection with securities offered pursuant to this prospectus supplement for any purpose. Pending application of the net proceeds as described above, we may initially invest the net proceeds in short-term, investment-grade, or interest-bearing securities.

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DILUTION

If you invest in our Class A common stock, your interest will be diluted immediately to the extent of the difference between the offering price per share and the as adjusted net tangible book value per share of our Class A common stock after this offering.

As of June 30, 2024, our net tangible book value was $59.1 million, or $1.82 per share of Class A common stock. Net tangible book value per share represents the amount of our tangible assets less our liabilities divided by 32,386,088, the total number of shares of our Class A common stock outstanding as of June 30, 2024.

After giving effect to the assumed sale of our Class A common stock in the aggregate amount of $50,000,000 at an assumed offering price of $7.41 per share, the last reported sale price of our Class A common stock on The Nasdaq Global Market on August 6, 2024, and after deducting commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of June 30, 2024 would have been $107.2 million, or $2.74 per share of Class A common stock. This amount would represent an immediate increase in net tangible book value of $0.92 per share to our existing stockholders and an immediate dilution in net tangible book value of approximately $4.67 per share to new investors in this offering.

The following table illustrates this calculation on a per share basis. The as adjusted information is illustrative only and will adjust based on the actual price to the public, the actual number of shares sold and other terms of the offering determined at the time shares of our Class A common stock are sold pursuant to this prospectus supplement. The shares sold in this offering, if any, will be sold from time to time at various prices.

The table above assumes for illustrative purposes that an aggregate of 6,747,638 shares of our Class A common stock are sold pursuant to this prospectus supplement at a price of $7.41 per share, the last reported sale price of our Class A common stock on The Nasdaq Global Market on August 6, 2024, for aggregate gross proceeds of $50,000,000. The shares are being sold from time to time at various prices pursuant to the sales agreement with TD Cowen. A $1.00 increase in the assumed offering price of $7.41 per share shown in the table above, assuming all of our Class A common stock in the aggregate amount of $50,000,000 during the term of the sales agreement with TD Cowen is sold at that price, would increase our adjusted net tangible book value per share after the offering to $2.80 per share and increase the dilution per share to purchasers by approximately $0.94, after deducting commissions and estimated offering expenses payable by us. A $1.00 decrease in the assumed offering price of $7.41 per share shown in the table above, assuming all of our Class A common stock in the aggregate amount of $50,000,000 during the term of the sales agreement with TD Cowen is sold at that price, would decrease our adjusted net tangible book value per share after the offering to $2.67 per share and would decrease dilution per share to purchasers by approximately $0.93, after deducting commissions and estimated offering expenses payable by us. This information is supplied for illustrative purposes only.

For purposes of calculating as adjusted net tangible book value, the above table is based on 32,386,088 shares of our Class A common stock issued and outstanding as of June 30, 2024. The number of shares outstanding as of June 30, 2024 excludes:

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To the extent that outstanding options or warrants are exercised or outstanding restricted stock units vest, investors purchasing our Class A common stock in this offering will experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

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DESCRIPTION OF CAPITAL STOCK

Our authorized capital stock consists of 150,000,000 shares of Class A common stock, par value $0.0001 per share, 1,500,000 shares of Class B common stock, par value $0.0001 per share and 5,000,000 shares of preferred stock, par value $0.0001 per share, all of which is undesignated. As of June 30, 2024, there were 32,386,088 shares of our Class A common stock issued and outstanding and 967,759 shares of our Class B common stock issued and outstanding. As of June 30, 2024, we had approximately 105 record holders of our Class A common stock and two stockholders of record of our Class B common stock.

The following summary of certain provisions of our capital stock does not purport to be complete. You should refer to the section of this prospectus supplement entitled “Certain Provisions of Delaware Law and of Our amended and restated certificate of incorporation, as amended, and Restated Bylaws” and our amended and restated certificate of incorporation, as amended, and our restated bylaws, both of which are included as exhibits to the registration statement of which this prospectus supplement is a part. The summary below is also qualified by provisions of applicable law.

Common Stock

General

Holders of our Class A common stock and our Class B common stock have identical rights, provided that, (i) except as otherwise expressly provided in our amended and restated certificate of incorporation, as amended, or as required by applicable law, on any matter that is submitted to a vote by our stockholders, holders of our Class A common stock are entitled to one vote per share of Class A common stock, and holders of our Class B common stock are not entitled to any votes per share of Class B common stock, including for the election of directors, and (ii) holders of our Class A common stock have no conversion rights, while holders of our Class B common stock have the right to convert each share of our Class B common stock into one share of Class A common stock at such holder’s election, provided that as a result of such conversion, such holder would not beneficially own in excess of 4.99% of any class of our securities registered under the Exchange Act, except as expressly provided for in our amended and restated certificate of incorporation, as amended. However, this ownership limitation may be increased or decreased to any other percentage designated by such holder of Class B common stock upon 61 days’ notice to us. Our Class A common stock and Class B common stock do not have cumulative voting rights. Accordingly, the holders of a majority of the outstanding shares of Class A common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they so choose, other than any directors that holders of any preferred stock we may issue may be entitled to elect. Subject to preferences that may be applicable to any then outstanding preferred stock, holders of our Class A common stock and Class B common stock are entitled to receive ratably those dividends, if any, as may be declared by the board of directors out of legally available funds. In the event of our liquidation, dissolution or winding up, the holders of our Class A common stock and Class B common stock will be entitled to share ratably in the assets legally available for distribution to stockholders after the payment of or provision for all of our debts and other liabilities, subject to the prior rights of any preferred stock then outstanding. Holders of our Class A common stock and Class B common stock have no preemptive rights or other subscription rights and there is no redemption or sinking funds provisions applicable to our Class A common stock and Class B common stock. All outstanding shares of our Class A common stock and Class B common stock as of the date of this prospectus supplement and, upon issuance and sale, all shares of Class A common stock that we may offer pursuant to this prospectus supplement, will be duly authorized, validly issued, fully paid and nonassessable. The rights, preferences and privileges of holders of our Class A common stock and Class B common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future. The rights, preferences and privileges of our holders of Class A common stock and Class B common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future. Except as described under the “— Certain Provisions of Delaware Law and of our Amended and Restated Certificate of Incorporation, as amended,

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and Restated Bylaws” section below, the affirmative vote of a majority of the shares of Class A common stock present in person or by proxy, is generally required to take action under our amended and restated certificate of incorporation, as amended, and restated bylaws.

Transfer Agent and Registrar

The transfer agent and registrar for our Class A common stock is Equiniti Trust Company, LLC. The transfer agent and registrar’s address is 48 Wall Street, Floor 23, New York, New York 10005.

Stock Exchange Listing

Our Class A common stock is listed for trading on The Nasdaq Global Market under the symbol “SERA.” Our Class B common stock is not listed for trading on any securities exchange, and we do not plan to list the Class B common stock on any securities exchange.

Preferred Stock

Our board of directors has the authority, without action by our stockholders, to designate and issue up to an aggregate of 5,000,000 shares of preferred stock in one or more series. Our board of directors can designate the rights, preferences and privileges of the shares of each series and any of its qualifications, limitations or restrictions. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of Class A common stock and Class B common stock. The issuance of preferred stock, while providing flexibility in connection with possible future financings and acquisitions and other corporate purposes could, under certain circumstances, have the effect of restricting dividends on our Class A common stock and Class B common stock, diluting the voting power of our Class A common stock, impairing the liquidation rights of our Class A common stock and Class B common stock, or delaying, deferring or preventing a change in control of our company, which might harm the market price of our Class A common stock. Our board of directors will make any determination to issue such shares based on its judgment as to our company’s best interests and the best interests of our stockholder.

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CERTAIN PROVISIONS OF DELAWARE LAW AND OF OUR AMENDED AND RESTATED CERTIFICATE OF INCORPORATION, AS AMENDED, AND RESTATED BYLAWS

Anti-Takeover Effects of Delaware Law, Our Amended and Restated Certificate of Incorporation and Our Restated bylaws

Our amended and restated certificate of incorporation, as amended, and restated bylaws include a number of provisions that may have the effect of encouraging persons considering unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather than pursue non-negotiated takeover attempts. These provisions include the items described below.

Board Composition and Filling Vacancies

In accordance with our amended and restated certificate of incorporation, as amended, our board of directors is divided into three classes serving three-year terms, with one class being elected each year. Our amended and restated certificate of incorporation, as amended, also provides that directors may be removed only for cause and then only by the affirmative vote of the holders of majority of the shares then entitled to vote at an election of directors. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of our board of directors, will only be able to be filled by the affirmative vote of a majority of our directors then in office, even if less than a quorum.

No Written Consent of Stockholders

Our amended and restated certificate of incorporation, as amended, provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting.

Meetings of Stockholders

Our restated bylaws provide that only a majority of the members of our board of directors then in office may call special meetings of stockholders and only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders. Our restated bylaws limit the business that may be conducted at an annual meeting of stockholders to those matters properly brought before the meeting.

Advance Notice Requirements

Our restated bylaws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days or more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. The notice must contain certain information specified in our restated bylaws. These provisions may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to obtain control of our company.

Amendment to Bylaws and Certificate of Incorporation

As required by the Delaware General Corporation Law, any amendment of our amended and restated certificate of incorporation, as amended, must first be approved by a majority of our board of directors and, if required by law or our amended and restated certificate of incorporation, as amended, thereafter be approved by a

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majority of the outstanding shares entitled to vote on the amendment, and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, directors, limitation of liability, exclusive jurisdiction of Delaware Courts and the amendment of our restated bylaws and amended and restated certificate of incorporation, as amended, must be approved by not less than 75% of the outstanding shares entitled to vote on the amendment, and not less than 75% of the outstanding shares of each class entitled to vote thereon as a class. Our restated bylaws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the restated bylaws; and may also be amended by the affirmative vote of at least 75% of the outstanding shares entitled to vote on the amendment, or, if the board of directors recommends that the stockholders approve the amendment, by the affirmative vote of the majority of the outstanding shares entitled to vote on the amendment.

Section 203 of the Delaware General Corporation Law

We are subject to the provisions of Section 203 of the Delaware General Corporation Law. In general, Section 203 prohibits a publicly-held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. An “interested stockholder” is a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15% or more of the corporation’s voting stock.

Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

A Delaware corporation may “opt out” of these provisions with an express provision in its original certificate of incorporation or an express provision in its amended and restated certificate of incorporation or restated bylaws resulting from a stockholders’ amendment approved by at least a majority of the outstanding voting shares. We have not opted out of these provisions. As a result, mergers or other takeover or change in control attempts of us may be discouraged or prevented.

Exclusive Jurisdiction of Certain Actions

Our amended and restated certificate of incorporation, as amended, provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, the federal district court for the District of Delaware or other state courts of the State of Delaware) will be the sole and exclusive forum for any state law claim for: (1) any derivative action or proceeding brought on our behalf; (2) any action or proceeding asserting a claim of breach of a fiduciary duty or other wrongdoing by any of our directors, officers, employees or agents to us or our stockholders; (3) any action or proceeding asserting a claim against us arising pursuant to any provision of the

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Delaware General Corporation Law or our amended and restated certificate of incorporation, as amended, or restated bylaws (in each case, as they may be amended from time to time); (4) any action or proceeding to interpret, apply, enforce or determine the validity of our amended and restated certificate of incorporation, as amended, or restated bylaws; (5) any action or proceeding as to which the Delaware General Corporation Law confers jurisdiction to the Court of Chancery of the State of Delaware; or (6) any action asserting a claim against us or any of our directors, officers or employees that is governed by the internal affairs doctrine. The choice of forum provision does not apply to any actions arising under the Exchange Act. Our amended and restated certificate of incorporation, as amended, further provides that, unless we consent in writing to an alternative forum, the United States District Court for the District of Utah will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act of 1933, as amended (the “Securities Act”). We have chosen the United States District Court for the District of Utah as the exclusive forum for such Securities Act causes of action because our principal executive offices are located in Salt Lake City, Utah. In addition, our amended and restated certificate of incorporation, as amended, provides that any person or entity purchasing or otherwise acquiring any interest in shares of our common stock is deemed to have notice of and consented to the foregoing provisions.

The choice of forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or any of our current or former director, officer, other employee, agent, or stockholder to the company, which may discourage such claims against us or any of our current or former director, officer, other employee, agent, or stockholder to the company and result in increased costs for investors to bring a claim. Alternatively, if a court were to find the choice of forum provisions contained in our amended and restated certificate of incorporation, as amended, to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, which could harm our business, results of operations and financial condition.

Limitation of Liability and Indemnification

Section 145(a) of the Delaware General Corporation Law provides, in general, that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation), because he or she is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, suit or proceeding, if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful.

Section 145(b) of the Delaware General Corporation Law provides, in general, that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure a judgment in its favor because the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action or suit if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, except that no indemnification shall be made with respect to any claim, issue or matter as to which he or she shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or other adjudicating court determines that, despite the adjudication of liability but in view of all of the circumstances of the case, he or she is fairly and reasonably entitled to indemnity for such expenses that the Court of Chancery or other adjudicating court shall deem proper.

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Section 145(g) of the Delaware General Corporation Law provides, in general, that a corporation may purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against any liability asserted against such person and incurred by such person in any such capacity, or arising out of his or her status as such, whether or not the corporation would have the power to indemnify the person against such liability under Section 145 of the Delaware General Corporation Law.

Our amended and restated certificate of incorporation, as amended, provides that no director or officer of our company shall be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duty as a director or officer, except for liability (1) for any breach of the director’s or of the officer’s duty of loyalty to us or our stockholders, (2) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (3) with respect to a director, under Section 174 of the Delaware General Corporation Law, and with respect to an officer, from any action by or in the right of our company, or (4) for any transaction from which a director or an officer derived an improper personal benefit. In addition, our amended and restated certificate of incorporation, as amended, provides that if the Delaware General Corporation Law is amended to authorize the further elimination or limitation of the liability of directors or officers, then the liability of a director or officer of our company shall be eliminated or limited to the fullest extent permitted by the Delaware General Corporation Law, as so amended. Our amended and restated certificate of incorporation, as amended, further provides that any repeal or modification of such article by our stockholders or amendment to the Delaware General Corporation Law will not adversely affect any right or protection existing at the time of such repeal or modification with respect to any acts or omissions occurring before such repeal or modification of a director serving at the time of such repeal or modification.

Our restated bylaws provide that we will indemnify each of our directors and officers and, in the discretion of our board of directors, certain employees, to the fullest extent permitted by the Delaware General Corporation Law as the same may be amended (except that in the case of amendment, only to the extent that the amendment permits us to provide broader indemnification rights than the Delaware General Corporation Law permitted us to provide prior to such the amendment) against any and all expenses, judgments, penalties, fines and amounts reasonably paid in settlement that are incurred by the director, officer or such employee or on the director’s, officer’s or employee’s behalf in connection with any threatened, pending or completed proceeding or any claim, issue or matter therein, to which he or she is or is threatened to be made a party because he or she is or was serving as a director, officer or employee of our company, or at our request as a director, partner, trustee, officer, employee or agent of another corporation, partnership, joint venture, trust, employee benefit plan or other enterprise, if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of our company and, with respect to any criminal proceeding, had no reasonable cause to believe his or her conduct was unlawful. Article VII, Section 2 of our restated bylaws further provides for the advancement of expenses to each of our directors and, in the discretion of the board of directors, to certain officers and employees.

In addition, our restated bylaws provide that the right of each of our directors and officers to indemnification and advancement of expenses shall be a contract right and shall not be exclusive of any other right now possessed or hereafter acquired under any statute, provision of our amended and restated certificate of incorporation, as amended, or our restated bylaws, agreement, vote of stockholders or otherwise. Furthermore, Article VII, Section 5 of our restated bylaws authorizes us to provide insurance for our directors, officers and employees, against any liability, whether or not we would have the power to indemnify such person against such liability under the Delaware General Corporation Law or the provisions of Article VII, Section 1 of our restated bylaws.

We have entered into indemnification agreements with each of our directors and our executive officers. These agreements will provide that we will indemnify each of our directors and such officers to the fullest extent permitted by law and our amended and restated certificate of incorporation, as amended, and our restated bylaws.

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We also maintain a general liability insurance policy, which covers certain liabilities of directors and officers of our company arising out of claims based on acts or omissions in their capacities as directors or officers.

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PLAN OF DISTRIBUTION

We have entered into a sales agreement with TD Cowen, under which we may issue and sell from time to time up to $50,000,000 of our Class A common stock through or to TD Cowen as our sales agent or principal. Sales of our Class A common stock, if any, will be made at market prices by any method that is deemed to be an “at the market offering” as defined in Rule 415 under the Securities Act. Sales pursuant to the sales agreement may be made through an affiliate of TD Cowen.

TD Cowen will offer our Class A common stock subject to the terms and conditions of the sales agreement on a daily basis or as otherwise agreed upon by us and TD Cowen. We will designate the maximum amount of Class A common stock to be sold through TD Cowen on a daily basis or otherwise determine such maximum amount together with TD Cowen. Subject to the terms and conditions of the sales agreement, TD Cowen will use its commercially reasonable efforts to sell on our behalf all of the shares of Class A common stock requested to be sold by us. We may instruct TD Cowen not to sell Class A common stock if the sales cannot be effected at or above the price designated by us in any such instruction. TD Cowen or we may suspend the offering of our Class A common stock being made through TD Cowen under the sales agreement upon proper notice to the other party. TD Cowen and we each have the right, by giving written notice as specified in the sales agreement, to terminate the sales agreement in each party’s sole discretion at any time.

The aggregate compensation payable to TD Cowen as sales agent equals 3.0% of the gross proceeds of the shares sold through it pursuant to the sales agreement. We have also agreed to reimburse TD Cowen up to $75,000 of TD Cowen’s actual outside legal expenses incurred by TD Cowen in connection with this offering. We estimate that the total expenses of the offering payable by us, excluding commissions payable to TD Cowen under the sales agreement, will be approximately $370,000.

The remaining sales proceeds, after deducting any expenses payable by us and any transaction fees imposed by any governmental, regulatory, or self-regulatory organization in connection with the sales, will equal our net proceeds for the sale of such Class A common stock.

TD Cowen will provide written confirmation to us following the close of trading on The Nasdaq Global Market on each day in which Class A common stock is sold through it as sales agent under the sales agreement. Each confirmation will include the number of shares of Class A common stock sold through it as sales agent on that day, the volume weighted average price of the shares sold, the percentage of the daily trading volume and the net proceeds to us.

We will report at least quarterly the number of shares of Class A common stock sold through TD Cowen under the sales agreement, the net proceeds to us and the compensation paid by us to TD Cowen in connection with the sales of Class A common stock.

Settlement for sales of Class A common stock will occur, unless the parties agree otherwise, on the first business day that is also a trading day following the date on which any sales were made in return for payment of the net proceeds to us. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

In connection with the sales of our Class A common stock on our behalf, TD Cowen will be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation paid to TD Cowen will be deemed to be underwriting commissions or discounts. We have agreed in the sales agreement to provide indemnification and contribution to TD Cowen against certain liabilities, including liabilities under the Securities Act. As sales agent, TD Cowen will not engage in any transactions that stabilize our Class A common stock.

Our Class A common stock is listed on The Nasdaq Global Market and trades under the symbol “SERA.” The transfer agent of our Class A common stock is Equiniti Trust Company, LLC.

TD Cowen and/or its affiliates have provided, and may in the future provide, various investment banking and other financial services for us for which services they have received and, may in the future receive, customary fees.

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LEGAL MATTERS

Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston, Massachusetts, will pass upon certain legal matters relating to this offering. Goodwin Procter LLP, New York, New York, is acting as counsel to TD Securities (USA) LLC in connection with this offering.

EXPERTS

Ernst & Young LLP, independent registered public accounting firm, has audited our financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2023, as set forth in their report, which is incorporated by reference in this prospectus supplement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information requirements of the Exchange Act, and in accordance therewith, file periodic reports, proxy statements and other information with the SEC. SEC filings are available at the SEC’s web site at http://www.sec.gov.

This prospectus supplement is only part of a registration statement on Form S-3 that we have filed with the SEC under the Securities Act, and therefore omits certain information contained in the registration statement. We have also filed exhibits and schedules with the registration statement that are excluded from this prospectus supplement, and you should refer to the applicable exhibit or schedule for a complete description of any statement referring to any contract or other document.

We also maintain a website at www.seraprognostics.com, through which you can access our SEC filings. The information set forth on our website is not part of this prospectus supplement.

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INCORPORATION OF INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” information that we file with them. Incorporation by reference allows us to disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus supplement, and information that we file later with the SEC will automatically update and supersede this information. We filed a registration statement on Form S-3 under the Securities Act with the SEC with respect to the securities we may offer pursuant to this prospectus supplement. This prospectus supplement omits certain information contained in the registration statement, as permitted by the SEC. You should refer to the registration statement, including the exhibits, for further information about us and the securities we may offer pursuant to this prospectus supplement. Statements in this prospectus supplement regarding the provisions of certain documents filed with, or incorporated by reference in, the registration statement are not necessarily complete and each statement is qualified in all respects by that reference. Copies of all or any part of the registration statement, including the documents incorporated by reference or the exhibits, may be obtained upon payment of the prescribed rates at the offices of the SEC listed above in “Where You Can Find More Information.” The documents we are incorporating by reference are:

We also incorporate by reference all documents we subsequently file with the SEC (other than information furnished pursuant to Item 2.02 or Item 7.01 of Form 8-K or as otherwise permitted by SEC rules) pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the initial filing of the registration statement of which this prospectus supplement is a part (including prior to the effectiveness of the registration statement) and prior to the termination of the offering.

Information in this prospectus supplement supersedes related information in the documents listed above, and information in subsequently filed documents supersedes related information in each of this prospectus supplement and the incorporated documents.

We will promptly provide, without charge to you, upon written or oral request, a copy of any or all of the documents incorporated by reference in this prospectus supplement, other than the exhibits, unless the exhibits are specifically incorporated by reference. Requests should be directed to:

Sera Prognostics, Inc.

Attn: Investor Relations,

2749 East Parleys Way, Suite 200

Salt Lake City, Utah 84109

Telephone: (801) 990-0520

You may also access these documents, free of charge on the SEC’s website at www.sec.gov or on our website at www.seraprognostics.com. Information contained on our website is not incorporated by reference into this prospectus supplement, and you should not consider any information on, or that can be accessed from, our website as part of this prospectus supplement.

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You should rely only on the information incorporated by reference or provided in this prospectus supplement. We have not authorized anyone to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus supplement or in the documents incorporated by reference is accurate as of any date other than the date on the front of this prospectus supplement or those documents.

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PROSPECTUS

$100,000,000

Sera Prognostics, Inc.

CLASS A COMMON STOCK

PREFERRED STOCK

DEBT SECURITIES

WARRANTS

RIGHTS

UNITS

We may offer and sell up to $100,000,000 of securities from time to time in one or more offerings. This prospectus will allow us to issue, from time to time at prices and on terms to be determined at or prior to the time of the offering, any combination of the securities described in this prospectus, either individually or in units. We may also offer Class A common stock or preferred stock upon conversion of or exchange for the debt securities; Class A common stock upon conversion of or exchange for the preferred stock; or Class A common stock, preferred stock or debt securities upon the exercise of warrants or rights.

This prospectus describes the general terms of these securities and the general manner in which these securities will be offered. We will provide you with the specific terms of any offering in one or more supplements to this prospectus. The prospectus supplements will also describe the specific manner in which these securities will be offered and may also supplement, update or amend information contained in this document. You should read this prospectus and any prospectus supplement, as well as any documents incorporated by reference into this prospectus or any prospectus supplement, carefully before you invest.

Our securities may be sold directly by us to you, through agents designated from time to time or to or through underwriters or dealers. For additional information on the methods of sale, you should refer to the section titled “Plan of Distribution” in this prospectus and in the applicable prospectus supplement. If any underwriters or agents are involved in the sale of our securities with respect to which this prospectus is being delivered, the names of such underwriters or agents and any applicable fees, commissions or discounts and details regarding options to purchase additional shares, if any, will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds that we expect to receive from such sale will also be set forth in a prospectus supplement.

Our Class A common stock is listed on The Nasdaq Global Market under the symbol “SERA.” On August 6, 2024, the last reported sale price of our Class A common stock was $7.41 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on The Nasdaq Global Market or any securities market or other securities exchange of the securities covered by the prospectus supplement. Prospective purchasers of our securities are urged to obtain current information as to the market prices of our securities, where applicable.

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks that we have described on page 6 of this prospectus under the caption “Risk Factors.” We may include specific risk factors in supplements to this prospectus under the caption “Risk Factors.” This prospectus may not be used to sell our securities unless accompanied by a prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is August 13, 2024.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a shelf registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or SEC, using a “shelf” registration process. Under this shelf registration process, we may from time to time offer shares of our Class A common stock and preferred stock, various series of debt securities and/or warrants or rights to purchase any of such securities, up to a total aggregate offering price of $100,000,000, either individually or in units, in one or more offerings, at prices and on terms to be set forth in one or more supplements to this prospectus at the time of an offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering, including, to the extent applicable, designation or classification; aggregate principal amount or aggregate offering price; maturity; any rates and times of payment of interest or dividends; any redemption, conversion or sinking fund terms; any voting or other rights; and any conversion or exercise prices. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings.

This prospectus does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits and the prospectus supplement, as applicable. The prospectus supplement may also add, update or change information contained or incorporated by reference in this prospectus. However, no prospectus supplement will offer a security that is not registered and described in this prospectus at the time of its effectiveness. This prospectus, together with the applicable prospectus supplements and the documents incorporated by reference into this prospectus, includes all material information relating to the offering of securities under this prospectus. You should carefully read this prospectus, the applicable prospectus supplement, the information and documents incorporated herein by reference and the additional information under the headings “Where You Can Find More Information” and “Incorporation of Documents by Reference” before making an investment decision.

You should rely only on the information we have provided or incorporated by reference in this prospectus or any prospectus supplement. We have not authorized anyone to provide you with information different from that contained or incorporated by reference in this prospectus. No dealer, salesperson or other person is authorized to give any information or to represent anything not contained or incorporated by reference in this prospectus or any prospectus supplement. You must not rely on any unauthorized information or representation. This prospectus is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. You should assume that the information in this prospectus or any prospectus supplement is accurate only as of the date on the front of the document and that any information we have incorporated herein by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of a security.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in this prospectus or any prospectus supplement were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

This prospectus may not be used to consummate sales of our securities unless it is accompanied by a prospectus supplement. To the extent there are inconsistencies between any prospectus supplement, this prospectus and any documents incorporated by reference, the document with the most recent date will control.

Unless the context otherwise requires, “Sera Prognostics,” “the Company,” “we,” “us,” “our” and similar terms refer to Sera Prognostics, Inc. and its subsidiaries.

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PROSPECTUS SUMMARY

The following is a summary of what we believe to be the most important aspects of our business and the offering of our securities under this prospectus. We urge you to read this entire prospectus, including the more detailed consolidated financial statements, notes to the consolidated financial statements and other information incorporated by reference from our other filings with the SEC or included in any applicable prospectus supplement. Investing in our securities involves risks. Therefore, carefully consider the risk factors set forth in any prospectus supplements and in our most recent annual and quarterly filings with the SEC, as well as other information in this prospectus and any prospectus supplements and the documents incorporated by reference herein or therein, before purchasing our securities. Each of the risk factors could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our securities.

Overview of Sera

We are a women’s health company utilizing our proprietary proteomics and bioinformatics platform, and significant data resources, to improve maternal and neonatal health by discovering, developing, and commercializing blood-based biomarker tests and predictive analytic products and services. Our vision is to deliver pivotal and actionable information to pregnant women, their physicians, and health care payers to significantly enhance a mother’s pregnancy journey, improve maternal and neonatal health, and dramatically reduce health care costs. We believe that our method of combining the disciplines of proteomics and bioinformatics with rigorous clinical testing, data, and economic analysis enables us to provide physicians and expectant mothers with personally insightful, clinically meaningful, and economically impactful information designed to improve the pregnancy experience and outcomes for mothers and babies.

There are approximately 140 million births globally each year, and approximately 3.7 million births annually in the United States. Of these, it is estimated that as many as 30% are affected by various complications (i.e., a high-risk pregnancy), including: preterm birth, preeclampsia, fetal growth restriction, stillbirth, hypertension of pregnancy, gestational diabetes, and others. In many cases these complications have profound short- and long-term health consequences for the mother and baby. These health consequences of preterm birth alone are estimated to be approximately $25 billion annually in the United States. This underscores that existing methods to predict adverse pregnancy outcomes are insufficient for timely and effective proactive management for the vast majority of high-risk pregnancies. We believe that positive patient outcomes are the result of appropriate care, and the primary differentiator of patient care should be based on a determination of risk informed by a number of factors including our novel diagnostic tests.

Our first commercial product, the PreTRM test, is the only broadly validated, commercially available blood-based biomarker test to accurately predict the risk of a premature delivery, also known as preterm birth. The PreTRM test is a non-invasive blood test given to a pregnant woman, carrying a single fetus, during weeks 18 through 20 of gestation that provides an accurate prediction of the expectant mother’s risk of delivering spontaneously before 37 weeks’ gestation. Our commercialization strategy includes conducting clinical trials to demonstrate the health and economic benefits of early and accurate detection of preterm birth risk coupled with well-recognized interventions in higher risk patients, illustrating these benefits to healthcare providers and insurance payers, and providing convenient access to the test through streamlined specimen collection options. Beyond demonstration of efficacy, we look forward to studying the effectiveness and implementation of the PreTRM test in a real-world setting. Clinical trials conducted to date include the Prediction and Prevention of Preterm Birth, or the PREVENT-PTB Study, Serum Assessment of Preterm Birth Outcomes Compared to Historical Controls study, or the AVERT PRETERM TRIAL, and the Prematurity Risk Assessment Combined With Clinical Interventions for Improving Neonatal outcoMEs study, or the PRIME study. Manuscript results of these studies demonstrate consistency in the reported beneficial impact of the PreTRM test-and-treat strategy. Specifically, this includes evidence of a prolongation of gestation, shortened hospital or neonatal intensive care unit, or NICU, length of stay, and improvements in measures of neonatal morbidity/mortality. Our studies demonstrate a model indicating that by identifying and intervening in at-risk pregnancies, not identifiable by

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other approaches, babies destined for premature delivery remain in utero longer. This prolongation of gestation in the preterm period leads to more mature babies that require shorter hospital/NICU stays due to improved neonatal health. The PRIME study, for which enrollment was stopped due to efficacy at the interim analysis and is being prepared for publication, includes the same Primary and Secondary outcomes as the AVERT PRETERM TRIAL and affords the continued assessment of this model.

We believe market adoption by both health care providers and payers should be aided by the publications of our PREVENT-PTB study sub-analysis and the peer-reviewed positive data from our AVERT PRETERM TRIAL, as well as upcoming publications, including the results of our PRIME study and other real-world evidence studies. We believe the data that will be published in coming years, together with our current body of evidence, will further demonstrate the clinical and economic utility of our test.

In December 2023, we announced that the Data Safety Monitoring Board, or DSMB, overseeing our PRIME study recommended stopping enrollment due to efficacy, reporting that either co-primary endpoints, neonatal hospital length of stay and composite neonatal morbidity and mortality, met the stopping criteria for statistical significance at the pre-planned interim analysis. We adopted the DSMB’s recommendation and stopped PRIME study enrollment to focus on analyzing and reporting the available data. In May 2024, deliveries of all PRIME study participants were complete, inclusive of the approximately 2,000 remaining participants who were enrolled but had not delivered before enrollment was stopped in December 2023 per DSMB recommendation. All mothers and babies within the study have left the hospital and data monitoring for the final PRIME dataset is in progress. Manuscripts reporting study results, including top-line and exploratory analyses, are being prepared for submission and peer review after final analysis expected in fall 2024.

We have built an advanced, proprietary, and scalable proteomics and bioinformatics platform to characterize the biology of pregnancy and to discover and validate key protein biomarkers found in blood that are highly accurate predictors of dynamic changes that occur during pregnancy. By incorporating our proprietary technology platform into our rigorous data-driven development process, we have created a differentiated approach for effectively addressing major milestones, conditions, and features of pregnancy. We believe our large and growing pregnancy dataset (clinical, demographic, proteomic) is a substantial asset for understanding pregnancy complications, health inequities, and the personal pregnancy journey. We envision that our comprehensive approach will enable us to fully characterize one of the most important periods in the lives of women and their babies, and will help to improve their well-being.

We are actively discovering and developing several additional biomarker tests to predict other specific major conditions of pregnancy, such as a pregnancy risk prediction panel test. We believe these tests have the potential to offer significant health benefits to women and their babies. Among other products, we are developing a test designed to provide a more accurate estimate of the delivery date for expectant mothers for the purposes of planning maternity leave, required support, travel arrangements, and related considerations.

We have taken steps to significantly reduce our annual operating expenses across all aspects of our business and we believe our cash runway is sufficient to enable us to operate into 2027 based on our existing operating plans. We will continue to evaluate the allocation of our resources as we focus our efforts to accelerate the market adoption of our PreTRM test and the development and launch of additional pipeline products and services. Our evidence portfolio continues to grow with the publication of the PREVENT-PTB study sub-analysis of the potential benefit of care coordination and low-dose aspirin paired with PreTRM test results.

We recently announced the publication of the positive results from the AVERT PRETERM TRIAL in Diagnostics, an international, peer-reviewed, open access journal on medical diagnosis. Diagnostics highlighted this study on the cover of the journal issue. Notable results indicated an 18% reduction in severe neonatal morbidity and mortality. Additionally, there was a 7-day reduction in the mean neonatal hospital length of stay among neonates with the longest stays. The trial also showed an increase in the average gestational age at birth before 32 weeks by 2.48 weeks. Furthermore, there was a 28-day reduction in the neonatal length of hospital stay

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for babies born before 32 weeks’ gestation, significantly reducing the time spent in the hospital for those at risk of the earliest delivery. Significant reductions in neonatal morbidity and mortality were also reported, as well as hospital and NICU lengths of stay, in the entire intent-to-treat population. The test-and-treat strategy was linked to decreased odds of preterm birth and spontaneous preterm birth at various gestational ages.

Our real-world evidence implementation programs, targeting to expand PreTRM clinical utility data and replicate randomized controlled trial evidence in the real world, have been developed for study launches anticipated in the second half of 2024 and in 2025.

We recently completed validation of certain whole-blood collection and whole-blood compatible testing technologies, and have begun marketing and processing whole-blood specimens. This evolution to whole-blood collection will remove laborious specimen processing steps such as centrifugation and enable in-office physician or at-home consumer collection channels. We believe that whole-blood collection technologies, paired with ambient specimen shipment approaches, may enable greater market penetration and an optimal customer experience, while also potentially lowering costs.

We will continue to opportunistically pursue contracts with private and governmental payers and health systems with new positive data from the PREVENT-PTB study, the AVERT PRETERM TRIAL, and the PRIME study, along with real-world evidence studies and other data we plan to generate, and we believe these efforts may eventually result in material revenues.

Our Corporate Information

Our corporate headquarters are located at 2749 East Parleys Way, Suite 200, Salt Lake City, Utah 84109, and our telephone number is (801) 990-0520. Our website address is https://www.seraprognostics.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.

Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K and all amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, are available free of charge through the investor relations page of our website as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.

All brand names or trademarks appearing in this prospectus are the property of their respective holders. Use or display by us of other parties’ trademarks, or products in this prospectus is not intended to, and does not, imply a relationship with, or endorsements or sponsorship of, us by the trademark.

Implications of Being an Emerging Growth Company and a Smaller Reporting Company

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, as amended, or the JOBS Act. As an emerging growth company, we may take advantage of specified reduced disclosure and other requirements that are otherwise applicable generally to public companies. These provisions include:

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We may take advantage of these exemptions until the fifth anniversary of our initial public offering or such earlier time that we are no longer an emerging growth company. We would cease to be an emerging growth company on the date that is the earliest of (i) the last day of the fiscal year in which we have total annual gross revenue of $1.235 billion or more; (ii) December 31, 2026; (iii) the date on which we have issued more than $1.0 billion in nonconvertible debt during the previous three years; or (iv) the last day of the fiscal year in which we are deemed to be a large accelerated filer under the rules of the SEC, which means the market value of our common stock that is held by non-affiliates exceeds $700 million as of the prior June 30th. We may choose to take advantage of some but not all of these exemptions. We have taken advantage of reduced reporting requirements in this prospectus. Accordingly, the information contained herein may be different from the information you receive from other public companies in which you hold stock. We are in the process of evaluating the benefits of relying on other exemptions and reduced reporting requirements under the JOBS Act. Subject to certain conditions, as an emerging growth company, we may rely on certain of these exemptions, including without limitation, providing an auditor’s attestation report on our system of internal controls over financial reporting pursuant to Section 404(b) of the Sarbanes-Oxley Act.

We are also a “smaller reporting company” as defined in the Exchange Act. We may continue to be a smaller reporting company even after we are no longer an emerging growth company. We may take advantage of certain of the scaled disclosures available to smaller reporting companies until the fiscal year following the determination that our voting and non-voting common stock held by non-affiliates is more than $250 million measured on the last business day of our second fiscal quarter, or our annual revenues are less than $100 million during the most recently completed fiscal year and our voting and non-voting common stock held by non-affiliates is more than $700 million measured on the last business day of our second fiscal quarter.

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RISK FACTORS

Investing in our securities involves significant risk. The prospectus supplement applicable to each offering of our securities will contain a discussion of the risks applicable to an investment in Sera Prognostics, Inc. Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading “Risk Factors” in the applicable prospectus supplement, together with all of the other information contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus. You should also consider the risks, uncertainties and assumptions discussed under the heading “Risk Factors” included in our most recent annual report on Form 10-K, as revised or supplemented by our subsequent quarterly reports on Form 10-Q or our subsequent current reports on Form 8-K that we have filed with the SEC, all of which are incorporated herein by reference, and which may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference in this prospectus include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Exchange Act, that relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Words such as, but not limited to, “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will,” “would,” or the negative of these words or other comparable terminology, are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements include, among other things, statements about:

Although we believe that we have a reasonable basis for each forward-looking statement contained in this prospectus and incorporated by reference in this prospectus, we caution you that these statements are based on our projections of the future that are subject to a number of risks, uncertainties, and assumptions. Moreover, we operate in a very competitive and rapidly changing environment, and new risks emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or

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the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. We have included important cautionary statements in this prospectus or in the documents incorporated by reference in this prospectus, particularly in the “Risk Factors” section, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. For a summary of such factors, please refer to the section entitled “Risk Factors” in this prospectus, as updated and supplemented by the discussion of risks and uncertainties under “Risk Factors” contained in any supplements to this prospectus and in our most recent annual report on Form 10-K, as revised or supplemented by our subsequent quarterly reports on Form 10-Q or our current reports on Form 8-K, as well as any amendments thereto, as filed with the SEC and which are incorporated herein by reference. The information contained in this document is believed to be current as of the date of this document. We do not intend to update any of the forward-looking statements after the date of this document to conform these statements to actual results or to changes in our expectations, except as required by law.

In light of these assumptions, risks and uncertainties, the results and events discussed in the forward-looking statements contained in this prospectus or in any document incorporated herein by reference might not occur. Investors are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this prospectus or the date of the document incorporated by reference in this prospectus. We are not under any obligation, and we expressly disclaim any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise. All subsequent forward-looking statements attributable to us or to any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section.

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USE OF PROCEEDS

Unless otherwise indicated in the applicable prospectus supplement, we intend to use any net proceeds from the sale of securities under this prospectus for our operations, the commercialization of the PreTRM test, and the further development and potential commercialization of any or all of our product candidates and future product candidates, and other general corporate purposes, including, but not limited to, working capital, intellectual property protection, investments, acquisitions and collaborations. We have not determined the amounts we plan to spend on any of the areas listed above or the timing of these expenditures. As a result, our management will have broad discretion to allocate the net proceeds, if any, we receive in connection with securities offered pursuant to this prospectus for any purpose. Pending application of the net proceeds as described above, we may initially invest the net proceeds in short-term, investment-grade, or interest-bearing securities.

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DESCRIPTION OF COMMON STOCK

We are authorized to issue 150,000,000 shares of Class A common stock, par value $0.0001 per share, and 1,500,000 shares of Class B common stock, par value $0.0001 per share. On June 30, 2024, we had 32,386,088 shares of Class A common stock outstanding, 967,759 shares of Class B common stock outstanding, approximately 105 record holders of our Class A common stock, and two stockholders of record of our Class B common stock

The following summary of certain provisions of our common stock does not purport to be complete. You should refer to our amended and restated certificate of incorporation, as amended, and our restated bylaws, both of which are included as exhibits to the registration statement of which this prospectus is a part. The summary below is also qualified by provisions of applicable law.

General

Holders of our Class A common stock and our Class B common stock have identical rights, provided that, (i) except as otherwise expressly provided in our amended and restated certificate of incorporation, as amended, or as required by applicable law, on any matter that is submitted to a vote by our stockholders, holders of our Class A common stock are entitled to one vote per share of Class A common stock, and holders of our Class B common stock are not entitled to any votes per share of Class B common stock, including for the election of directors, and (ii) holders of our Class A common stock have no conversion rights, while holders of our Class B common stock have the right to convert each share of our Class B common stock into one share of Class A common stock at such holder’s election, provided that as a result of such conversion, such holder would not beneficially own in excess of 4.99% of any class of our securities registered under the Exchange Act, except as expressly provided for in our amended and restated certificate of incorporation, as amended. However, this ownership limitation may be increased or decreased to any other percentage designated by such holder of Class B common stock upon 61 days’ notice to us. Our Class A common stock and Class B common stock do not have cumulative voting rights. Accordingly, the holders of a majority of the outstanding shares of Class A common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they so choose, other than any directors that holders of any preferred stock we may issue may be entitled to elect. Subject to preferences that may be applicable to any then outstanding preferred stock, holders of our Class A common stock and Class B common stock are entitled to receive ratably those dividends, if any, as may be declared by the board of directors out of legally available funds. In the event of our liquidation, dissolution or winding up, the holders of our Class A common stock and Class B common stock will be entitled to share ratably in the assets legally available for distribution to stockholders after the payment of or provision for all of our debts and other liabilities, subject to the prior rights of any preferred stock then outstanding. Holders of our Class A common stock and Class B common stock have no preemptive rights or other subscription rights and there is no redemption or sinking funds provisions applicable to our Class A common stock and Class B common stock. All outstanding shares of our Class A common stock and Class B common stock as of the date of this prospectus and, upon issuance and sale, all shares of Class A common stock that we may offer pursuant to this prospectus, will be duly authorized, validly issued, fully paid and nonassessable. The rights, preferences and privileges of holders of our Class A common stock and Class B common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future. The rights, preferences and privileges of our holders of Class A common stock and Class B common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future. Except as described under the “Certain Provisions of Delaware Law and of our Amended and Restated Certificate of Incorporation, as amended, and Restated Bylaws” section below, the affirmative vote of a majority of the shares of Class A common stock present in person or by proxy, is generally required to take action under our amended and restated certificate of incorporation, as amended, and restated bylaws.

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Transfer Agent and Registrar

The transfer agent and registrar for our Class A common stock is Equiniti Trust Company, LLC. The transfer agent and registrar’s address is 48 Wall Street, Floor 23, New York, New York 10005.

Stock Exchange Listing

Our Class A common stock is listed for trading on The Nasdaq Global Market under the symbol “SERA.” Our Class B common stock is not listed for trading on any securities exchange, and we do not plan to list the Class B common stock on any securities exchange.

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DESCRIPTION OF PREFERRED STOCK

We are authorized to issue 5,000,000 shares of blank check preferred stock, par value $0.0001 per share. As of the date of this prospectus, no shares of our preferred stock were outstanding or designated. The following summary of certain provisions of our preferred stock does not purport to be complete. You should refer to our amended and restated certificate of incorporation, as amended, and our restated bylaws, both of which are included as exhibits to the registration statement of which this prospectus is a part. The summary below is also qualified by provisions of applicable law.

General

Our board of directors has the authority, without action by our stockholders, to designate and issue up to an aggregate of 5,000,000 shares of preferred stock in one or more series. Our board of directors can designate the rights, preferences and privileges of the shares of each series and any of its qualifications, limitations or restrictions. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of Class A common stock and Class B common stock. The issuance of preferred stock, while providing flexibility in connection with possible future financings and acquisitions and other corporate purposes could, under certain circumstances, have the effect of restricting dividends on our Class A common stock and Class B common stock, diluting the voting power of our Class A common stock, impairing the liquidation rights of our Class A common stock and Class B common stock, or delaying, deferring or preventing a change in control of our company, which might harm the market price of our Class A common stock. Our board of directors will make any determination to issue such shares based on its judgment as to our company’s best interests and the best interests of our stockholder.

If we offer a specific series of preferred stock under this prospectus, we will describe the terms of the preferred stock in the prospectus supplement for such offering and will file a copy of the certificate establishing the terms of the preferred stock with the SEC. To the extent required, this description will include:

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Transfer Agent and Registrar

The transfer agent and registrar for our preferred stock will be set forth in the applicable prospectus supplement.

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DESCRIPTION OF DEBT SECURITIES

The following description, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the debt securities that we may offer under this prospectus. While the terms we have summarized below will apply generally to any future debt securities we may offer pursuant to this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. If we so indicate in a prospectus supplement, the terms of any debt securities offered under such prospectus supplement may differ from the terms we describe below, and to the extent the terms set forth in a prospectus supplement differ from the terms described below, the terms set forth in the prospectus supplement shall control.

We may sell from time to time, in one or more offerings under this prospectus, debt securities, which may be senior or subordinated. We will issue any such senior debt securities under a senior indenture that we will enter into with a trustee to be named in the senior indenture. We will issue any such subordinated debt securities under a subordinated indenture, which we will enter into with a trustee to be named in the subordinated indenture. We have filed forms of these documents as exhibits to the registration statement, of which this prospectus is a part. We use the term “indentures” to refer to either the senior indenture or the subordinated indenture, as applicable. The indentures will be qualified under the Trust Indenture Act of 1939, or the Trust Indenture Act, as in effect on the date of the indenture. We use the term “debenture trustee” to refer to either the trustee under the senior indenture or the trustee under the subordinated indenture, as applicable.

The following summaries of material provisions of the senior debt securities, the subordinated debt securities and the indentures are subject to, and qualified in their entirety by reference to, all the provisions of the indenture applicable to a particular series of debt securities.

General

Each indenture provides that debt securities may be issued from time to time in one or more series and may be denominated and payable in foreign currencies or units based on or relating to foreign currencies. Neither the senior indenture nor any subordinated indenture limits the amount of debt securities that may be issued thereunder. Each indenture provides that the specific terms of any series of debt securities shall be set forth in, or determined pursuant to, an authorizing resolution and/or a supplemental indenture, if any, relating to such series.

We will describe in each prospectus supplement the following terms relating to a series of debt securities:

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We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

Conversion or Exchange Rights

We will set forth in the prospectus supplement the terms, if any, on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale; No Protection in Event of a Change of Control or Highly Leveraged Transaction

The indentures do not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of all or substantially all of our assets. However, any successor to or acquirer of such assets must assume all of our obligations under the indentures or the debt securities, as appropriate.

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions that may afford holders of the debt securities protection in the event we have a change of control or in the event of a highly leveraged transaction (whether or not such transaction results in a change of control), which could adversely affect holders of debt securities.

Events of Default Under the Indenture

The following are events of default under the indentures with respect to any series of debt securities that we may issue:

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No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any other series of debt securities. The occurrence of an event of default may constitute an event of default under any bank credit agreements we may have in existence from time to time. In addition, the occurrence of certain events of default or an acceleration under the indenture may constitute an event of default under certain of our other indebtedness outstanding from time to time.

If an event of default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than a majority in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the debenture trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of and premium and accrued and unpaid interest, if any, on all debt securities of that series. Before a judgment or decree for payment of the money due has been obtained with respect to debt securities of any series, the holders of a majority in principal amount of the outstanding debt securities of that series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) may rescind and annul the acceleration if all events of default, other than the non-payment of accelerated principal, premium, if any, and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the applicable indenture (including payments or deposits in respect of principal, premium or interest that had become due other than as a result of such acceleration). We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an event of default.

Subject to the terms of the indentures, if an event of default under an indenture shall occur and be continuing, the debenture trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the debenture trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the debenture trustee, or exercising any trust or power conferred on the debenture trustee, with respect to the debt securities of that series, provided that:

A holder of the debt securities of any series will only have the right to institute a proceeding under the indentures or to appoint a receiver or trustee, or to seek other remedies if:

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These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the applicable debenture trustee regarding our compliance with specified covenants in the applicable indenture.

Modification of Indenture; Waiver

The debenture trustee and we may change the applicable indenture without the consent of any holders with respect to specific matters, including:

In addition, under the indentures, the rights of holders of a series of debt securities may be changed by us and the debenture trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) that is affected. However, the debenture trustee and we may make the following changes only with the consent of each holder of any outstanding debt securities affected:

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on any debt security of that series or in respect of a covenant or provision, which cannot be modified or amended without the consent of the holder of each outstanding debt security of the series affected; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

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Discharge

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for obligations to:

In order to exercise our rights to be discharged with respect to a series, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, the premium, if any, and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange, and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we otherwise specify in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indentures provide that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company or another depositary named by us and identified in a prospectus supplement with respect to that series.

At the option of the holder, subject to the terms of the indentures and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indentures and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange or in the applicable indenture, we will make no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem the debt securities of any series, we will not be required to:

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Information Concerning the Debenture Trustee

The debenture trustee, other than during the occurrence and continuance of an event of default under the applicable indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the debenture trustee under such indenture must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the debenture trustee is under no obligation to exercise any of the powers given it by the indentures at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check which we will mail to the holder. Unless we otherwise indicate in a prospectus supplement, we will designate the corporate trust office of the debenture trustee in the City of New York as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the debenture trustee for the payment of the principal of or any premium or interest on any debt securities which remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the security thereafter may look only to us for payment thereof.

Governing Law

The indentures and the debt securities will be governed by and construed in accordance with the laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.

Subordination of Subordinated Debt Securities

Our obligations pursuant to any subordinated debt securities will be unsecured and will be subordinate and junior in priority of payment to certain of our other indebtedness to the extent described in a prospectus supplement. The subordinated indenture does not limit the amount of senior indebtedness we may incur. It also does not limit us from issuing any other secured or unsecured debt.

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DESCRIPTION OF WARRANTS

General

We may issue warrants to purchase shares of our common stock, preferred stock and/or debt securities in one or more series together with other securities or separately, as described in the applicable prospectus supplement. Below is a description of certain general terms and provisions of the warrants that we may offer. Particular terms of the warrants will be described in the warrant agreements and the prospectus supplement relating to the warrants.

The applicable prospectus supplement will contain, where applicable, the following terms of and other information relating to the warrants:

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Exercise of Warrants

Each warrant will entitle the holder to purchase for cash such shares of our common stock and/or our preferred stock and/or our debt securities at such exercise price as shall in each case be set forth in, or be determinable as set forth in, the prospectus supplement relating to the warrants offered thereby. Warrants may be exercised at any time up to the close of business on the expiration date set forth in the prospectus supplement relating to the warrants offered thereby. After the close of business on the expiration date, unexercised warrants will become void.

The warrants may be exercised as set forth in the prospectus supplement relating to the warrants offered. Upon receipt of payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the shares of our common stock and/or our preferred stock and/or our debt securities purchasable upon such exercise. If less than all of the warrants represented by such warrant certificate are exercised, a new warrant certificate will be issued for the remaining warrants.

Warrant Agent

The name and address of the warrant agent for any warrants we offer, if one is appointed, will be set forth in the applicable prospectus supplement.

Enforceability of Rights by Holders of Warrants

If we appoint a warrant agent, any warrant agent will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

Outstanding Warrants

As of June 30, 2024, we had warrants to purchase an aggregate of 2,649,720 Class A shares of common stock outstanding, having a weighted-average exercise price equal to $12.88 per share, subject to certain adjustments as specified in the warrants.

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DESCRIPTION OF RIGHTS

General

We may issue rights to our stockholders to purchase shares of our common stock, preferred stock or the other securities described in this prospectus. We may offer rights separately or together with one or more additional rights, debt securities, preferred stock, common stock or warrants, or any combination of those securities in the form of units, as described in the applicable prospectus supplement. Each series of rights will be issued under a separate rights agreement to be entered into between us and a bank or trust company, as rights agent. The rights agent will act solely as our agent in connection with the certificates relating to the rights of the series of certificates and will not assume any obligation or relationship of agency or trust for or with any holders of rights certificates or beneficial owners of rights. The following description sets forth certain general terms and provisions of the rights to which any prospectus supplement may relate. The particular terms of the rights to which any prospectus supplement may relate and the extent, if any, to which the general provisions may apply to the rights so offered will be described in the applicable prospectus supplement. To the extent that any particular terms of the rights, rights agreement or rights certificates described in a prospectus supplement differ from any of the terms described below, then the terms described below will be deemed to have been superseded by that prospectus supplement. We encourage you to read the applicable rights agreement and rights certificate for additional information before you decide whether to purchase any of our rights.

We will provide in a prospectus supplement the following terms of the rights being issued:

Each right will entitle the holder of rights to purchase for cash the principal amount of shares of common stock, preferred stock or other securities at the exercise price provided in the applicable prospectus supplement. Rights may be exercised at any time up to the close of business on the expiration date for the rights provided in the applicable prospectus supplement.

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Holders may exercise rights as described in the applicable prospectus supplement. Upon receipt of payment and the rights certificate properly completed and duly executed at the corporate trust office of the rights agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the shares of common stock, preferred stock or other securities, as applicable, purchasable upon exercise of the rights. If less than all of the rights issued in any rights offering are exercised, we may offer any unsubscribed securities directly to persons other than stockholders, to or through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby arrangements, as described in the applicable prospectus supplement.

Rights Agent

The name and address of the rights agent for any rights we offer will be set forth in the applicable prospectus supplement.

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DESCRIPTION OF UNITS

The following description, together with the additional information that we include in any applicable prospectus supplements summarizes the material terms and provisions of the units that we may offer under this prospectus. While the terms we have summarized below will apply generally to any units that we may offer under this prospectus, we will describe the particular terms of any series of units in more detail in the applicable prospectus supplement. The terms of any units offered under a prospectus supplement may differ from the terms described below.

We will incorporate by reference from reports that we file with the SEC, the form of unit agreement that describes the terms of the series of units we are offering, and any supplemental agreements, before the issuance of the related series of units. The following summaries of material terms and provisions of the units are subject to, and qualified in their entirety by reference to, all the provisions of the unit agreement and any supplemental agreements applicable to a particular series of units. We urge you to read the applicable prospectus supplements related to the particular series of units that we may offer under this prospectus, as well as any related free writing prospectuses and the complete unit agreement and any supplemental agreements that contain the terms of the units.

General

We may issue units consisting of common stock, preferred stock, one or more debt securities, warrants or rights for the purchase of common stock, preferred stock and/or debt securities in one or more series, in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each security included in the unit. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date.

We will describe in the applicable prospectus supplement the terms of the series of units being offered, including:

The provisions described in this section, as well as those set forth in any prospectus supplement or as described under “Description of Common Stock,” “Description of Preferred Stock,” “Description of Debt Securities,” “Description of Warrants,” and “Description of Rights” will apply to each unit, as applicable, and to any common stock, preferred stock, debt security, warrant, or right included in each unit, as applicable.

Unit Agent

The name and address of the unit agent, if any, for any units we offer will be set forth in the applicable prospectus supplement.

Issuance in Series

We may issue units in such amounts and in such numerous distinct series as we determine.

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Enforceability of Rights by Holders of Units

Each unit agent will act solely as our agent under the applicable unit agreement and will not assume any obligation or relationship of agency or trust with any holder of any unit. A single bank or trust company may act as unit agent for more than one series of units. A unit agent will have no duty or responsibility in case of any default by us under the applicable unit agreement or unit, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a unit may, without the consent of the related unit agent or the holder of any other unit, enforce by appropriate legal action its rights as holder under any security included in the unit.

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CERTAIN PROVISIONS OF DELAWARE LAW AND OF OUR AMENDED AND RESTATED CERTIFICATE OF INCORPORATION, AS AMENDED, AND RESTATED BYLAWS

Anti-Takeover Effects of Delaware Law, Our Amended and Restated Certificate of Incorporation, as amended, and Our Restated bylaws

Our amended and restated certificate of incorporation, as amended, and restated bylaws include a number of provisions that may have the effect of encouraging persons considering unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather than pursue non-negotiated takeover attempts. These provisions include the items described below.

Board Composition and Filling Vacancies

In accordance with our amended and restated certificate of incorporation, as amended, our board of directors is divided into three classes serving three-year terms, with one class being elected each year. Our amended and restated certificate of incorporation, as amended, also provides that directors may be removed only for cause and then only by the affirmative vote of the holders of majority of the shares then entitled to vote at an election of directors. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of our board of directors, will only be able to be filled by the affirmative vote of a majority of our directors then in office, even if less than a quorum.

No Written Consent of Stockholders

Our amended and restated certificate of incorporation, as amended, provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting.

Meetings of Stockholders

Our restated bylaws provide that only a majority of the members of our board of directors then in office may call special meetings of stockholders and only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders. Our restated bylaws limit the business that may be conducted at an annual meeting of stockholders to those matters properly brought before the meeting.

Advance Notice Requirements

Our restated bylaws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days or more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. The notice must contain certain information specified in our restated bylaws. These provisions may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to obtain control of our company.

Amendment to Bylaws and Certificate of Incorporation

As required by the Delaware General Corporation Law, any amendment of our amended and restated certificate of incorporation, as amended, must first be approved by a majority of our board of directors and, if required by law or our amended and restated certificate of incorporation, as amended, thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment, and a majority of the outstanding shares of each class

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entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, directors, limitation of liability, exclusive jurisdiction of Delaware Courts and the amendment of our restated bylaws and amended and restated certificate of incorporation, as amended, must be approved by not less than 75% of the outstanding shares entitled to vote on the amendment, and not less than 75% of the outstanding shares of each class entitled to vote thereon as a class. Our restated bylaws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the restated bylaws; and may also be amended by the affirmative vote of at least 75% of the outstanding shares entitled to vote on the amendment, or, if the board of directors recommends that the stockholders approve the amendment, by the affirmative vote of the majority of the outstanding shares entitled to vote on the amendment.

Section 203 of the Delaware General Corporation Law

We are subject to the provisions of Section 203 of the Delaware General Corporation Law. In general, Section 203 prohibits a publicly-held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. An “interested stockholder” is a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15% or more of the corporation’s voting stock.

Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

A Delaware corporation may “opt out” of these provisions with an express provision in its original certificate of incorporation or an express provision in its amended and restated certificate of incorporation or restated bylaws resulting from a stockholders’ amendment approved by at least a majority of the outstanding voting shares. We have not opted out of these provisions. As a result, mergers or other takeover or change in control attempts of us may be discouraged or prevented.

Exclusive Jurisdiction of Certain Actions

Our amended and restated certificate of incorporation, as amended, provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, the federal district court for the District of Delaware or other state courts of the State of Delaware) will be the sole and exclusive forum for any state law claim for: (1) any derivative action or proceeding brought on our behalf; (2) any action or proceeding asserting a claim of breach of a fiduciary duty or other wrongdoing by any of our directors, officers, employees or agents to us or our stockholders; (3) any action or proceeding asserting a claim against us arising pursuant to any provision of the Delaware General Corporation Law or our amended and restated certificate of incorporation, as amended, or restated bylaws (in

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each case, as they may be amended from time to time); (4) any action or proceeding to interpret, apply, enforce or determine the validity of our amended and restated certificate of incorporation, as amended, or restated bylaws; (5) any action or proceeding as to which the Delaware General Corporation Law confers jurisdiction to the Court of Chancery of the State of Delaware; or (6) any action asserting a claim against us or any of our directors, officers or employees that is governed by the internal affairs doctrine. The choice of forum provision does not apply to any actions arising under the Exchange Act. Our amended and restated certificate of incorporation, as amended, further provides that, unless we consent in writing to an alternative forum, the United States District Court for the District of Utah will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act of 1933, as amended (the “Securities Act”). We have chosen the United States District Court for the District of Utah as the exclusive forum for such Securities Act causes of action because our principal executive offices are located in Salt Lake City, Utah. In addition, our amended and restated certificate of incorporation, as amended, provides that any person or entity purchasing or otherwise acquiring any interest in shares of our common stock is deemed to have notice of and consented to the foregoing provisions.

The choice of forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or any of our current or former director, officer, other employee, agent, or stockholder to the company, which may discourage such claims against us or any of our current or former director, officer, other employee, agent, or stockholder to the company and result in increased costs for investors to bring a claim. Alternatively, if a court were to find the choice of forum provisions contained in our amended and restated certificate of incorporation, as amended, to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, which could harm our business, results of operations and financial condition.

Limitation of Liability and Indemnification

Section 145(a) of the Delaware General Corporation Law provides, in general, that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation), because he or she is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, suit or proceeding, if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful.

Section 145(b) of the Delaware General Corporation Law provides, in general, that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure a judgment in its favor because the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action or suit if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, except that no indemnification shall be made with respect to any claim, issue or matter as to which he or she shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or other adjudicating court determines that, despite the adjudication of liability but in view of all of the circumstances of the case, he or she is fairly and reasonably entitled to indemnity for such expenses that the Court of Chancery or other adjudicating court shall deem proper.

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Section 145(g) of the Delaware General Corporation Law provides, in general, that a corporation may purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against any liability asserted against such person and incurred by such person in any such capacity, or arising out of his or her status as such, whether or not the corporation would have the power to indemnify the person against such liability under Section 145 of the Delaware General Corporation Law.

Our amended and restated certificate of incorporation, as amended, provides that no director or officer of our company shall be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duty as a director or officer, except for liability (1) for any breach of the director’s or of the officer’s duty of loyalty to us or our stockholders, (2) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (3) with respect to a director, under Section 174 of the Delaware General Corporation Law, and with respect to an officer, from any action by or in the right of our company, or (4) for any transaction from which a director or an officer derived an improper personal benefit. In addition, our amended and restated certificate of incorporation, as amended, provides that if the Delaware General Corporation Law is amended to authorize the further elimination or limitation of the liability of directors or officers, then the liability of a director or officer of our company shall be eliminated or limited to the fullest extent permitted by the Delaware General Corporation Law, as so amended. Our amended and restated certificate of incorporation, as amended, further provides that any repeal or modification of such article by our stockholders or amendment to the Delaware General Corporation Law will not adversely affect any right or protection existing at the time of such repeal or modification with respect to any acts or omissions occurring before such repeal or modification of a director serving at the time of such repeal or modification.

Our restated bylaws provide that we will indemnify each of our directors and officers and, in the discretion of our board of directors, certain employees, to the fullest extent permitted by the Delaware General Corporation Law as the same may be amended (except that in the case of amendment, only to the extent that the amendment permits us to provide broader indemnification rights than the Delaware General Corporation Law permitted us to provide prior to such the amendment) against any and all expenses, judgments, penalties, fines and amounts reasonably paid in settlement that are incurred by the director, officer or such employee or on the director’s, officer’s or employee’s behalf in connection with any threatened, pending or completed proceeding or any claim, issue or matter therein, to which he or she is or is threatened to be made a party because he or she is or was serving as a director, officer or employee of our company, or at our request as a director, partner, trustee, officer, employee or agent of another corporation, partnership, joint venture, trust, employee benefit plan or other enterprise, if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of our company and, with respect to any criminal proceeding, had no reasonable cause to believe his or her conduct was unlawful. Article VII, Section 2 of our restated bylaws further provides for the advancement of expenses to each of our directors and, in the discretion of the board of directors, to certain officers and employees.

In addition, our restated bylaws provide that the right of each of our directors and officers to indemnification and advancement of expenses shall be a contract right and shall not be exclusive of any other right now possessed or hereafter acquired under any statute, provision of our amended and restated certificate of incorporation, as amended, or our restated bylaws, agreement, vote of stockholders or otherwise. Furthermore, Article VII, Section 5 of our restated bylaws authorizes us to provide insurance for our directors, officers and employees, against any liability, whether or not we would have the power to indemnify such person against such liability under the Delaware General Corporation Law or the provisions of Article VII, Section 1 of our restated bylaws.

We have entered into indemnification agreements with each of our directors and our executive officers. These agreements will provide that we will indemnify each of our directors and such officers to the fullest extent permitted by law and our amended and restated certificate of incorporation, as amended, and our restated bylaws.

We also maintain a general liability insurance policy, which covers certain liabilities of directors and officers of our company arising out of claims based on acts or omissions in their capacities as directors or officers.

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PLAN OF DISTRIBUTION

We may offer securities under this prospectus from time to time pursuant to underwritten public offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities (1) through underwriters or dealers, (2) through agents or (3) directly to one or more purchasers, or through a combination of such methods. We may distribute the securities from time to time in one or more transactions at:

We may directly solicit offers to purchase the securities being offered by this prospectus. We may also designate agents to solicit offers to purchase the securities from time to time, and may enter into arrangements for “at-the-market,” equity line or similar transactions. We will name in a prospectus supplement any underwriter or agent involved in the offer or sale of the securities.

If we utilize a dealer in the sale of the securities being offered by this prospectus, we will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale.

If we utilize an underwriter in the sale of the securities being offered by this prospectus, we will execute an underwriting agreement with the underwriter at the time of sale, and we will provide the name of any underwriter in the prospectus supplement which the underwriter will use to make resales of the securities to the public. In connection with the sale of the securities, we, or the purchasers of the securities for whom the underwriter may act as agent, may compensate the underwriter in the form of underwriting discounts or commissions. The underwriter may sell the securities to or through dealers, and the underwriter may compensate those dealers in the form of discounts, concessions or commissions.

With respect to underwritten public offerings, negotiated transactions and block trades, we will provide in the applicable prospectus supplement information regarding any compensation we pay to underwriters, dealers or agents in connection with the offering of the securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters within the meaning of the Securities Act, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions. We may enter into agreements to indemnify underwriters, dealers and agents against civil liabilities, including liabilities under the Securities Act, or to contribute to payments they may be required to make in respect thereof.

If so indicated in the applicable prospectus supplement, we will authorize underwriters, dealers or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in each applicable prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in each applicable prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

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One or more firms, referred to as “remarketing firms,” may also offer or sell the securities, if a prospectus supplement so indicates, in connection with a remarketing arrangement upon their purchase. Remarketing firms will act as principals for their own accounts or as our agents. These remarketing firms will offer or sell the securities in accordance with the terms of the securities. Each prospectus supplement will identify and describe any remarketing firm and the terms of its agreement, if any, with us and will describe the remarketing firm’s compensation. Remarketing firms may be deemed to be underwriters in connection with the securities they remarket. Remarketing firms may be entitled under agreements that may be entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

Certain underwriters may use this prospectus and any accompanying prospectus supplement for offers and sales related to market-making transactions in the securities. These underwriters may act as principal or agent in these transactions, and the sales will be made at prices related to prevailing market prices at the time of sale. Any underwriters involved in the sale of the securities may qualify as “underwriters” within the meaning of Section 2(a)(11) of the Securities Act. In addition, the underwriters’ commissions, discounts or concessions may qualify as underwriters’ compensation under the Securities Act and the rules of the Financial Industry Regulatory Authority, Inc., or FINRA.

Shares of our Class A common stock sold pursuant to the registration statement of which this prospectus is a part will be authorized for listing and trading on The Nasdaq Global Market. The applicable prospectus supplement will contain information, where applicable, as to any other listing on The Nasdaq Global Market or any securities market or other securities exchange of the securities covered by the prospectus supplement. Underwriters may make a market in our Class A common stock, but will not be obligated to do so and may discontinue any market making at any time without notice. We can make no assurance as to the liquidity of or the existence, development or maintenance of trading markets for any of the securities.

In order to facilitate the offering of the securities, certain persons participating in the offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. This may include over-allotments or short sales of the securities, which involve the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover such over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing the applicable security in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if the securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

The underwriters, dealers and agents may engage in other transactions with us, or perform other services for us, in the ordinary course of their business.

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LEGAL MATTERS

Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston, Massachusetts, will pass upon the validity of the issuance of the securities to be offered by this prospectus. Additional legal matters may be passed upon for us or any underwriters, dealers or agents, by counsel that we will name in the applicable prospectus supplement.

EXPERTS

Ernst & Young LLP, independent registered public accounting firm, has audited our financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2023, as set forth in their report, which is incorporated by reference in this prospectus and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the reporting requirements of the Securities Exchange Act of 1934, as amended, and file annual, quarterly and current reports, proxy statements and other information with the SEC. SEC filings are available at the SEC’s web site at http://www.sec.gov.

This prospectus is only part of a registration statement on Form S-3 that we have filed with the SEC under the Securities Act of 1933, as amended, and therefore omits certain information contained in the registration statement. We have also filed exhibits and schedules with the registration statement that are excluded from this prospectus, and you should refer to the applicable exhibit or schedule for a complete description of any statement referring to any contract or other document.

We also maintain a website at http://www.seraprognostics.com with information about our company and through which you may access these materials and other filings with the SEC free of charge as soon as reasonably practicable after they are filed electronically with, or furnished to, the SEC. Except for the documents incorporated by reference as described below under “Incorporation of Documents by Reference”, information contained on our website or any other website is not incorporated into this prospectus and does not constitute a part of this prospectus. Our website address referenced above is intended to be an inactive textual reference only and not an active hyperlink to our website.

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INCORPORATION OF DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” information that we file with them. Incorporation by reference allows us to disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. We filed a registration statement on Form S-3 under the Securities Act of 1933, as amended, with the SEC with respect to the securities we may offer pursuant to this prospectus. This prospectus omits certain information contained in the registration statement, as permitted by the SEC. You should refer to the registration statement, including the exhibits, for further information about us and the securities we may offer pursuant to this prospectus. Statements in this prospectus regarding the provisions of certain documents filed with, or incorporated by reference in, the registration statement are not necessarily complete and each statement is qualified in all respects by that reference. Copies of all or any part of the registration statement, including the documents incorporated by reference or the exhibits, may be obtained upon payment of the prescribed rates at the offices of the SEC listed above in “Where You Can Find More Information.” The documents we are incorporating by reference are:

We also incorporate by reference all documents we subsequently file with the SEC (other than information furnished pursuant to Item 2.02 or Item 7.01 of Form 8-K or as otherwise permitted by SEC rules) pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the initial filing of the registration statement of which this prospectus is a part (including prior to the effectiveness of the registration statement) and prior to the termination of the offering.

This prospectus is part of a registration statement on Form S-3 that we have filed with the SEC relating to the securities. As permitted by SEC rules, this prospectus does not contain all of the information included in the registration statement and the accompanying exhibits and schedules we file with the SEC. We have filed certain legal documents that control the terms of the Class A common stock offered by this prospectus as exhibits to the registration statement. We may file certain other legal documents that control the terms of the Class A common stock offered by this prospectus as exhibits to reports we file with the SEC. You may refer to the registration statement and the exhibits and schedules for more information about us and our securities. The registration statement and exhibits and schedules are also available through the SEC’s website at www.sec.gov.

We will provide, without charge and upon oral or written request, to each person, including any beneficial owner, to whom a copy of this prospectus has been delivered, a copy of any of the documents referred to above as being incorporated by reference into this prospectus but not delivered with it. You may obtain a copy of these filings, at no cost, by writing or calling us at Sera Prognostics, Inc., Attn: Investor Relations, 2749 East Parleys Way, Suite 200, Salt Lake City, Utah 84109, (801) 990-0520. Exhibits to the filings will not be provided, however, unless those exhibits have been specifically incorporated by reference in this prospectus.

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Up to $50,000,000

Sera Prognostics, Inc.

Class A Common Stock

PROSPECTUS SUPPLEMENT

TD Cowen

August 13, 2024