As filed with the Securities and Exchange Commission on June 24, 2022August 11, 2023

Registration No. 333-            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington,WASHINGTON, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

RAPT THERAPEUTICS, INC.Therapeutics, Inc.

(Exact name of registrant as specified in its charter)

561 Eccles Avenue

South San Francisco, California 94080

(650) 489-9000

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Brian Wong, M.D., Ph.D.

President and Chief Executive Officer

RAPT Therapeutics, Inc.

561 Eccles Avenue

South San Francisco, California 94080

(650) 489-9000

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Courtney M.W. Tygesson

Christina T. Roupas

Cooley LLP

110 NorthN. Wacker Drive

Suite 4200

Chicago, Illinois 60606IL 60606-1511

(312) 881-6500

Approximate date of commencement of proposed sale to the public:From time to time after the effective date of this Registration StatementStatement.

(Approximate date of commencement of proposed sale to the public)

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.box:  ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.box:  ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,”company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

The registrantRegistrant hereby amends this registration statementRegistration Statement on such date or dates as may be necessary to delay its effective date until the registrantRegistrant shall file a further amendment that specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This registration statement contains two prospectuses:

The base prospectus immediately follows this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be specified in a prospectus supplement to the base prospectus.

The prospectus relating to the Controlled Equity Offering^SM Sales Agreement immediately follows the base prospectus. The common stock that may be offered, issued and sold by RAPT under the Controlled Equity Offering^SM Sales Agreement prospectus is included in the $450,000,000 of securities that may be offered, issued and sold by RAPT under the base prospectus. Upon termination of the Controlled Equity Offering^SM Sales Agreement with Cantor Fitzgerald & Co. and Leerink Partners LLC, any portion of the $150,000,000 included in the Controlled Equity Offering^SM Sales Agreement prospectus that is not sold pursuant to the Controlled Equity Offering^SM Sales Agreement will be available for sale in other offerings pursuant to the base prospectus and a corresponding prospectus supplement, and if no shares are sold under the Controlled Equity Offering^SM Sales Agreement, the full $150,000,000 of securities may be sold in other offerings pursuant to the base prospectus and a prospectus supplement.

The information in this preliminary prospectus is not complete and may be changed. The selling stockholder named in this prospectusWe may not sell these securities or accept an offer to buy these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and the selling stockholder named in this prospectusit is not soliciting offers to buy these securities in any state or other jurisdiction where thesuch offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED JUNE 24, 2022AUGUST 11, 2023

PRELIMINARY PROSPECTUS

4,000,000 sharesProspectus

$450,000,000

Common stockStock

This prospectus relates to the proposed resale fromPreferred Stock

Debt Securities

Warrants

From time to time, ofwe may offer and sell up to 4,000,000 shares (the “Shares”)an aggregate amount of our$450,000,000 of any combination of the securities described in this prospectus, either individually or in combination with other securities. We may also offer common stock par value $0.0001 per share (the “common stock”), which are issuableor preferred stock upon conversion of debt securities, common stock upon conversion of preferred stock, or common stock, preferred stock or debt securities upon the exercise of pre-funded warrants to purchase shares of common stock (the “Pre-Funded Warrants”), by the selling stockholder named herein, together with any additional selling stockholders listed in a prospectus supplement (together with any of such stockholders’ transferees, pledgees, donees or successors).warrants.

We are registeringwill provide the offerspecific terms of these offerings and sale of the Shares from timesecurities in one or more supplements to time by the selling stockholderthis prospectus. We may also authorize one or more free writing prospectuses to satisfy the registration rights they were grantedbe provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectuses may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the issuanceapplicable prospectus supplement and any related free writing prospectuses, as well as any documents incorporated by reference, before buying any of the Pre-Funded Warrants. We will not receive any proceeds from the sale of the Shares by the selling stockholder.

The selling stockholder may offer and sell or otherwise dispose of the Shares described in this prospectus from time to time through public or private transactions at prevailing market prices, at prices related to prevailing market prices or at privately negotiated prices. The selling stockholder will bear all underwriting fees, commissions and discounts, if any, attributable to the sale of Shares and any transfer taxes. We will bear all other costs, expenses and fees in connection with the registration of the Shares. See “Plan of Distribution” for more information about how the selling stockholder may sell or dispose of the Shares.securities being offered.

Our common stock is listed on the Nasdaq Global Market under the trading symbol “RAPT.” On June 23, 2022,August 9, 2023, the closinglast reported sale price of our common stock was $19.32$24.05 per share. The applicable prospectus supplement will contain information, where applicable, as to other listings, if any, on the Nasdaq Global Market or other securities exchange of the securities covered by the applicable prospectus supplement.

We are an “emerging growth company” under the federal securities laws and are subject to reduced public company reporting requirements.

Investing in shares of our common stocksecurities involves a high degree of risk. YouBefore making an investment decision, you should review carefully the risks and uncertainties described inunder the section titledheading “Risk Factors” on page 58 of this prospectus and any similar section contained in the applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the documents that are incorporated by reference into this prospectus.

This prospectus may not be used to consummate a sale of securities unless accompanied by a prospectus supplement.

The securities may be sold by us directly to investors, through agents designated from time to time or to or through underwriters or dealers, on a continuous or delayed basis. The supplements to this prospectus will provide the specific terms of the plan of distribution. If any agents, underwriters or dealers are involved in the sale of any securities with respect to which this prospectus is being delivered, the names of such agents, underwriters or dealers and any applicable fees, commissions, discounts and options to purchase additional securities will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in 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                , 2022.2023.

TABLE OF CONTENTS

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by third parties. These data involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the industry in which we operate is necessarily subject to a high degree of uncertainty and risk due to a variety of factors, including those described in “Risk Factors” and elsewhere in this prospectus, any related prospectus supplement, documents incorporated by reference into this prospectus and any related or free writing prospectuses. These and other factors could cause results to differ materially from those expressed in the estimates made by the independent parties and by us.

This prospectus and any related prospectus supplement, including the information incorporated by reference into this prospectus and any related prospectus supplement, include trademarks, service marks and trade names owned by us or others. All trademarks, service marks and trade names included or incorporated by reference in this prospectus, any related prospectus supplement or any related free writing prospectuses are the property of their respective owners.

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RISK FACTORS

An investmentInvesting in our common stocksecurities involves a high degree of risk. PriorBefore deciding whether to making a decision about investinginvest in our common stock,securities, you should consider carefully the specific risk factors discussedrisks and uncertainties described under the heading “Risk Factors” contained in the sectionsapplicable prospectus supplement and any related free writing prospectuses, and discussed under the section entitled “Risk Factors” contained in our most recent Annual Report on Form 10-K and in our most recent Quarterly Report on Form 10-Q, as well as any amendments thereto reflected in subsequent filings with the SEC, which are incorporated by reference into this prospectus in their entirety, together with other information in this prospectus, the documents incorporated by reference and any applicable prospectus supplement and any free writing prospectusprospectuses that we may authorize. Theseauthorize for use in connection with this offering. The risks and uncertaintiesdescribed in these documents are not the only risks and uncertaintiesones we face. Additional risks and uncertainties not presently known to us, orface, but those that we currently view as immaterial,consider to be material. There may also impairbe other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our business.future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. If any of thethese risks or uncertainties described in our SEC filings or any additional risks and uncertainties actually occur,occurs, our business, financial condition, results of operations andor cash flow could be materially and adversely affected. In that case,seriously harmed. This could cause the trading price of our common stock couldto decline, and you might loseresulting in a loss of all or part of your investment. Please also read carefully the section below entitled “Special Note Regarding Forward-Looking Statements.”

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and any accompanying prospectus supplement, as well as the documents we have filed with the SEC that are incorporated by reference in this prospectus or any accompanying prospectus supplement contain forward-looking statements that involve risks, uncertainties and assumptions that, if they never materialize or prove incorrect, could cause our results to differ materially from those expressed or implied by such forward-looking statements. The statements contained in the prospectus and the documents we have filed with the SEC that are incorporated by reference that are not purely historical are forward-looking statements“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 Securities Exchange Act of 1934, or the Exchange Act. Forward-lookingThese statements are often identified by the use of words such as, but not limitedrelate to “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would” or the negative of those terms, and similar expressions that convey uncertainty of future events or outcomes to identify these forward-looking statements. Any statements contained herein that are not statements of historical factsour future operating or financial performance and involve known and unknown risks, uncertainties and other factors which may be deemedcause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Forward-looking statements may include, but are not limited to, statements about:

In some cases, you can identify forward-looking statements by terms such as “anticipates,” “believes,” “could,” “estimates,” “expects,” “may,” “plans,” “potential” “predicts,” “projects,” “should,” “will,” “would,” and similar expressions intended to identify forward-looking statements. These statements reflect our most recent Annual Reportcurrent views with respect to future events and are based on Form 10-Kassumptions and in our most recent Quarterly Report on Form 10-Q.

USE OF PROCEEDS

We will not receiveExcept as described in any ofapplicable prospectus supplement or in any free writing prospectuses we have authorized for use in connection with a specific offering, we currently intend to use the net proceeds from the sale of the Sharessecurities offered by us hereunder, if any, for working capital, capital expenditures and other general corporate purposes, including research and development expenses, or for any other purpose we describe in this offering. The selling stockholder will receive all of the proceeds from the sale of the Shares hereunder.applicable prospectus supplement.

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DESCRIPTION OF CAPITAL STOCK

The following summary description of our capital stock is based on the provisions of our amended and restated certificate of incorporation and amended and restated bylaws and the applicable provisions of the General Corporation Law of the State of Delaware (the “DGCL”). This information is qualified entirely by reference to the applicable provisions of our amended and restated certificate of incorporation and amended and restated bylaws. For information on how to obtain copies of our amended and restated certificate of incorporation and amended and restated bylaws, which are exhibits to the registration statement of which this prospectus is a part, see the sections titled “Where You Can Find Additional Information” and “Incorporation of Certain Information by Reference” in this prospectus.

General

Our authorized capital stock consists of 500,000,000 shares of common stock, $0.0001 par value per share, and 50,000,000 shares of preferred stock, $0.0001 par value per share. A description of material terms and provisions of our amended and restated certificate of incorporation, andor the Certificate of Incorporation, amended and restated bylaws, or the bylaws, and applicable provisions of the General Law of the State of Delaware, or the DGCL, affecting the rights of holders of our capital stock is set forth below. The description is intended as a summary, and is qualified in its entirety by reference to our amendedCertificate of Incorporation, our bylaws and restated certificate of incorporation and amended and restated bylaws.the DGCL.

Common Stock

Voting Rights. Each holder of common stock is entitled to one vote for each share of common stock held on all matters submitted to a vote of the stockholders, including the election of directors. The amendedCertificate of Incorporation and restated certificate of incorporation and amended and restated bylaws do not provide for cumulative voting rights in connection with election of directors unless, at the time of such election, we are subject to Section 2115(b) of the California General Corporation Law. The affirmative vote of holders of 66 2/3% of the voting power of all of the then-outstanding shares of capital stock, voting as a single class, will be required to amend certain provisions of our amended and restated certificateCertificate of incorporation,Incorporation, including provisions relating to amending our amended and restated bylaws, and removal of directors.

Dividends. Subject to preferences that may be applicable to any then outstanding preferred stock, the holders of outstanding shares of common stock may receive dividends, if any, as may be declared from time to time by ourthe board of directors out of legally available funds. We have never issued a dividend on shares of our common stock and we have no intention to do so in the future.

Liquidation. In the event we liquidate, dissolve or wind up, the assets legally available for distribution shall be distributed ratably to the holders of shares of common stock and preferred stock after payment of liabilities, subject to the satisfaction of any liquidation preference granted to the holders of any outstanding shares of preferred stock.

Rights and Preferences. Holders of common stock have no preemptive, conversion or subscription rights, and there are no redemption or sinking fund provisions applicable to the common stock. The rights, preferences and privileges of the holders of 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.

Fully Paid and Nonassessable. All outstanding shares of common stock are fully paid and nonassessable.

Preferred Stock

Our board of directors is authorized, subject to limitations prescribed by Delaware law, to issue up to 50,000,000 shares of preferred stock in one or more series, to establish from time to time the number of shares to be included in each series and to fix the designation, powers, preferences and rights of the shares of each series

certificate of designation relating to which we agreed to issue and sellthat series. We will file as an exhibit to the Investor in the Private Placement Pre-Funded Warrants to purchase an aggregate of 4,000,000 shares of common stock. Each Pre-Funded Warrant has an exercise price of $0.0001 per Share. The Pre-Funded Warrants are exercisable at any time after their original issuance and will not expire. The Private Placement closed on May 27, 2022.

The Pre-Funded Warrants issued in the Private Placement provide that the holder of the Pre-Funded Warrants will not have the right to exercise any portion of its Pre-Funded Warrants if such holder, together with its affiliates, would beneficially own in excess of 9.99% of the number of shares of common stock outstanding immediately after giving effect to such exercise (the “Beneficial Ownership Limitation”); provided, however, that the holder may increase or decrease the Beneficial Ownership Limitation by giving 61 days’ notice to the Company, but not to any percentage in excess of 19.99%.

The holders of the Pre-Funded Warrants must pay the exercise price in cash upon exercise of the Pre-Funded Warrants, unless such holders are utilizing the cashless exercise provision of the Pre-Funded Warrants. The Pre-Funded Warrants may be exercised (in the sole discretion of the holder), in whole or in part, at such time by means of a “cashless exercise” in which the holder of such Pre-Funded Warrants shall be entitled to receive that number of Shares determined according to the following formula:

[(A-B)*(X)]

(A)

Where:

A = the VWAP (as defined below) on the trading day immediately preceding the date of such election;

B = the exercise price then in effect; and

X = the number of Shares for which the Pre-Funded Warrants are being exercised (which shall include both the number of Shares issued to the holder thereof and the number of Shares subject to the portion of the Pre-Funded Warrants being cancelled in payment of the exercise price).

As used above, the “VWAP” means, for any date, the price determined by the first of the following clauses that applies: (i) if the common stock is then listed on the Nasdaq Global Select Market, the Nasdaq Global Market, the Nasdaq Capital Market or the New York Stock Exchange (such market, the “Trading Market”), the daily volume-weighted average price of the common stock for such date (or the nearest preceding date) on the Trading Market as reported by Bloomberg Financial L.P. (based on a “Trading Day” from 9:30 a.m. Eastern Time to 4:02 p.m. Eastern Time); (ii) the volume-weighted average price of the common stock for such date (or the nearest preceding date) on the OTC Bulletin Board; (iii) if the common stock is not then listed on a Trading Market or quoted on the OTC Bulletin Board and if prices for the common stock are then reported in the “Pink Sheets” published by the Pink Sheets, LLC (or a similar organization or agency succeeding to its functions of

Registration Rights

We are party to an amended and restated investor rights agreement that provides certain registration rights to certain holders of our common stock. The requisite holders of registrable securities pursuant to the registration rights agreement have waived their registration rights in connection with the filing of the registration statement of which this prospectus forms a part and any offering of securities pursuant to such registration statement.

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

Certificate of incorporation and bylaws. Our amendedCertificate of Incorporation and restated certificate of incorporation and amended and restated bylaws include a number of provisions that may deter or impede hostile takeovers or changes of control or management. These provisions include:

Issuance of undesignated preferred stock.

We designed these provisions to enhance the likelihood of continued stability in the composition of our board of directors and gaining controlits policies, to discourage certain types of transactions that may involve an actual or threatened acquisition of us, and to reduce our vulnerability to an unsolicited acquisition proposal. We also designed these provisions to discourage certain tactics that may be used in proxy fights. However, these provisions could have the effect of discouraging others from making tender offers for our shares and, as a consequence, they may also reduce fluctuations in the market price of our board of directors by filling the resulting vacancies with its own nominees.shares that could result from actual or rumored takeover attempts.

Stockholder action; special meetings of stockholders. Our amended and restated certificate of incorporation provides that our stockholders may not take action by written consent, but may only take action at annual or special meetings of our stockholders. Stockholders will not be permitted to cumulate their votes for the election

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of directors unless required by applicable law. Our amended and restated bylaws provide that only the chairman of our board of directors, chief executive officer or a majority of our board of directors may call special meetings of our stockholders.

Section 203 of the DGCL. Delaware General Corporation Law

We are subject to Section 203 of the DGCL, which prohibits a Delaware corporation from engaging in a business combination with any interested stockholder for a period of three years following the date the person became an interested stockholder, with the following exceptions:

In general, Section 203 of the DGCL defines business combination to include the following:

Section 203 of the DGCL defines an “interested stockholder” as an entity or person who, together with the entity’s or person’s affiliates and associates, beneficially owns, or is an affiliate of the corporation and within three years prior to the time of determination of interested stockholder status did own, 15% or more of the outstanding voting stock of the corporation. A Delaware corporation may “opt out” of these provisions with an express provision in its certificate of incorporation. We have not opted out of these provisions, which may as a result, discourage or prevent mergers or other takeover or change of control attempts of us.

Choice of Forum

Our Certificate of Incorporation provides that the Court of Chancery of the State of Delaware will be the exclusive forum for the following types of actions or proceedings under Delaware statutory or common law: (i) any derivative action or proceeding brought on our behalf; (ii) any action asserting a claim of breach of a fiduciary duty owed by any director, officer or other employee of our company to us or our stockholders; (iii) any action asserting a claim against us or any director or officer or other employee of our company arising pursuant to the General Corporation Law of the State of Delaware, our Certificate of Incorporation or bylaws; or (iv) any action asserting a claim against us or any director or officer or other employee of our company that is governed by the internal affairs doctrine. This provision would not apply to claims brought to enforce a duty or liability created by the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction. Our Certificate of Incorporation further provides that the federal district courts of the United States of America will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act.

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Transfer Agent and Registrar

Our transfer agent and registrar for our common stock is American Stock Transfer &Equinti Trust Company, LLC. The transfer agent for any series of preferred stock that we may offer under this prospectus will be named and described in the applicable prospectus supplement related to that series.

Listing on the Nasdaq Global Market

Our common stock is listed on the Nasdaq Global Market the symbol “RAPT.” 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 exchange of the preferred stock covered by such prospectus supplement.

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SELLING STOCKHOLDERDESCRIPTION OF DEBT SECURITIES

We have prepared this prospectus to allow the selling stockholder to offer and sellmay issue debt securities from time to time, upin one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to 4,000,000 Shares issuable uponany debt securities that we may offer under this prospectus, we will describe the exerciseparticular terms of any debt securities that we may offer in more detail in the Pre-Funded Warrants held byapplicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the selling stockholder. Forterms described below. Unless the context requires otherwise, whenever we refer to the indenture, we also are referring to any supplemental indentures that specify the terms of a descriptionparticular series of the Pre-Funded Warrants, see “Description of Capital Stock—Pre-Funded Warrants.”debt securities.

We are registeringwill issue the offer and sale ofdebt securities under the Shares held by the selling stockholder to satisfy certain registration obligationsindenture that we granted the selling stockholder in connectionwill enter into with the purchasetrustee named in the indenture. The indenture will be qualified under the Trust Indenture Act of 1939, as amended, or the Pre-Funded Warrants. PursuantTrust Indenture Act. We have filed the form of indenture as an exhibit to a Registration Rights Agreement, we have agreed to use commercially reasonable efforts to keep the registration statement of which this prospectus is a part, effective untiland supplemental indentures and forms of debt securities containing the earliestterms of the debt securities being offered will be filed as exhibits to occur of: (i) the date that all registrable securities covered by such registration statement have been soldof which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The following summary of material provisions of the debt securities and (ii) the dateindenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

General

The indenture does not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which all registrable securities covered by such registration statementmeans they may be sold without restriction pursuant to Rule 144.

The following table sets forth (i) the nameat a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may be issued with “original issue discount,” or OID, for U.S. federal income tax purposes because of interest payment and other characteristics or terms of the selling stockholder, (ii)debt securities. Material U.S. federal income tax considerations applicable to debt securities issued with OID will be described in more detail in any applicable prospectus supplement.

We will describe in the numberapplicable prospectus supplement the terms of shares beneficially owned by the selling stockholder, including series of debt securities being offered, including:

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Conversion or Exchange Rights

We will set forth in the applicable prospectus supplement the terms 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 settlement upon conversion or exchange and (iv)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 beneficially owned bysubject to adjustment.

Consolidation, Merger or Sale

Unless we provide otherwise in the selling stockholder assumingprospectus supplement applicable to a particular series of debt securities, the indenture will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of our assets as an entirety or substantially as an entirety. However, any successor to or acquirer of such assets (other than a subsidiary of ours) must assume all of our obligations under the Shares covered herebyindenture or the debt securities, as appropriate.

Events of Default under the Indenture

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are sold.events of default under the indenture with respect to any series of debt securities that we may issue:

Beneficial ownership is determined

If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the trustee or the holders of at least 25% in aggregate principal

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amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to the series and its consequences, except defaults or events of default regarding payment of principal, premium, if any, or interest, unless we have cured the default or event of default in accordance with the indenture. Any waiver shall cure the default or event of default.

Subject to the terms of the indenture, if an event of default under an indenture shall occur and be continuing, the 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 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 trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

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

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 trustee regarding our compliance with specified covenants in the indenture.

Modification of Indenture; Waiver

We and the trustee may change an indenture without the consent of any holders with respect to specific matters:

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In addition, under the indenture, the rights of holders of a series of debt securities may be changed by us and includes votingthe 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 that is affected. However, unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, we and the trustee may make the following changes only with the consent of each holder of any outstanding debt securities affected:

Discharge

Each indenture provides that we can elect to be discharged from our obligations with respect to our common stock. Except as indicatedone or more series of debt securities, except for specified obligations, including obligations to:

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In order to exercise our rights to be discharged, we believe, basedmust deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the information furnisheddebt 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 provide otherwise in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indenture provides 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 DTC, or another depositary named by us and identified in the applicable prospectus supplement with respect to that series. To the extent the debt securities of a series are issued in global form and as book-entry, a description of terms relating to any book-entry securities will be set forth in the applicable prospectus supplement.

At the option of the holder, subject to the terms of the indenture 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 indenture 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 namedpresents for transfer or exchange, we will impose 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 table below hasapplicable 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:

Information Concerning the Trustee

The trustee, other than during the occurrence and continuance of an event of default under an 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 trustee 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 trustee is under no obligation to exercise any of the powers given it by the indenture 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.

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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 that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee as our sole voting and investment powerpaying 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 trustee for the payment of the principal of or any premium or interest on any debt securities that 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 debt security thereafter may look only to us for payment thereof.

Governing Law

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

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements and in any related free writing prospectuses that we may authorize to be distributed to you, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and be issued in one or more series. Warrants may be offered independently or in combination with common stock, preferred stock or debt securities offered by any prospectus supplement. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. The following description of warrants will apply to the warrants offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of warrants may specify different or additional terms.

We have filed forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that may be offered as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that describe the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants. The following summaries of material terms and provisions of the warrants are subject to, and qualified in their entirety by reference to, all the provisions of the form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements applicable to a particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplement related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectuses, and the complete form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements, that contain the terms of the warrants.

General

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

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Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. The informationwarrants may be exercised as set forth in the table below is basedprospectus supplement relating to the warrants offered. Unless we otherwise specify in the applicable prospectus supplement, warrants may be exercised at any time up to the close of business on 29,646,821 sharesthe expiration date set forth in the prospectus supplement relating to the warrants offered thereby. After the close of our common stock outstandingbusiness on the expiration date, unexercised warrants will become void.

Upon receipt of payment and the warrant or warrant certificate, as applicable, properly completed and duly executed at the corporate trust office of June 16, 2022the warrant agent, if any, or any other office, including ours, indicated in the prospectus supplement, we will, as soon as practicable, issue and assumesdeliver the selling stockholder disposes ofsecurities purchasable upon such exercise. If less than all of the Shareswarrants (or the warrants represented by such warrant certificate) are exercised, a new warrant or a new warrant certificate, as applicable, will be issued for the remaining warrants.

Governing Law

Unless we otherwise specify in the applicable prospectus supplement, the warrants and any warrant agreements will be governed by and construed in accordance with the laws of the State of New York.

Enforceability of Rights by Holders of Warrants

Each warrant agent, if any, 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.

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LEGAL OWNERSHIP OF SECURITIES

We may issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Securities issued in global form will be registered in the name of the depositary or its participants. Consequently, for securities issued in global form, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a book-entry security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities in non-global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee and of any third parties employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

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For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with depositary participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of the indenture or for other purposes. In such an event, we would seek approval only from the holders, and not the indirect holders, of the securities. Whether and how the holders contact the indirect holders is up to the holders.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form or in street name, you should check with your own institution to find out:

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, DTC will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under the section entitled “Special Situations When a Global Security Will Be Terminated” in this prospectus. As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued in global form only, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

Special Considerations for Global Securities

The rights of an indirect holder relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We

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do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only in the form of a global security, an investor should be aware of the following:

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, the global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own name, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, the global security will terminate when the following special situations occur:

The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by thisthe applicable prospectus supplement. When a global security terminates, the depositary, and does not acquire beneficial ownership ofwe or any additional shares of common stock. The registrationapplicable trustee, is responsible for deciding the names of the Shares does not necessarily meaninstitutions that will be the selling stockholder will sell all or any portion of the Shares covered by this prospectus.

As used in this prospectus, the term “selling stockholder” includes the selling stockholder listed in the table below, together with any additional selling stockholders listed in a prospectus supplement, and their donees, pledgees, assignees, transferees, distributees and successors-in-interest that receive Shares in any non-sale transfer after the date of this prospectus.initial direct holders.

PLAN OF DISTRIBUTION

We are registeringmay sell the Shares to permit the resale of the Shares by the selling stockholdersecurities from time to time afterpursuant to underwritten public offerings, “at the datemarket” offerings as defined in Rule 415 under the Securities Act at negotiated prices, direct sales to the public, negotiated transactions, block trades or a combination of this prospectus upon exercise of the Pre-Funded Warrants.these methods. We will not receive any of the proceeds from the sale by the selling stockholder of the Shares. We will bear all fees and expenses incident to our obligation to register the Shares, except that, if the Shares are sold through underwriters or broker-dealers, the selling stockholder will be responsible for underwriting discounts or commissions or agent’s commissions.

The selling stockholder may sell all or a portion of the Shares beneficially owned by them and offered hereby from timesecurities to time directly or through one or more underwriters broker-dealers or agents. The Sharesdealers (acting as principal or agent), through agents, or directly to one or more purchasers. We may distribute the securities from time to time in one or more transactions:

A prospectus supplement or supplements (and any related free writing prospectuses that we may authorize to be provided to you) will describe the terms of the offering of the securities by us, including, to the extent applicable:

Only underwriters named in the prospectus supplement will be underwriters of the securities offered by the prospectus supplement. Dealers and agents participating in the distribution of the securities may be deemed to be underwriters, and compensation received by them on resale of the securities may be deemed to be underwriting discounts. If such dealers or agents were deemed to be underwriters, they may be subject to statutory liabilities under the Securities Act.

If underwriters are used in the sale, they will acquire the securities for their own account and may resell the securities from time to time in one or more transactions at a fixed prices, at prevailing market prices at the time of the sale,public offering price or at varying prices determined at the time of sale, or at negotiated prices. These sales may be effected in transactions, which may involve crosses or block transactions,

If the selling stockholder effects such transactions by selling Shares to or through underwriters, broker-dealers or agents, such underwriters, broker-dealers or agents may receive commissions in the form of discounts, concessions or commissions from the selling stockholder or commissions from purchasers of the Shares for whom they may act as agent or to whom they may sell as principal (which discounts, concessions or commissions as to particular underwriters, broker-dealers or agents may be in excess of those customary in the types of transactions involved). In connection with sales of the Shares or otherwise, the selling stockholder may enter into hedging transactions with broker-dealers, which may in turn engage in short sales of the Shares in the course of hedging in positions they assume. The selling stockholder may also sell Shares short and deliver Shares covered by this prospectus to close out short positions and to return borrowed shares in connection with such short sales. The selling stockholder may also loan or pledge Shares to broker-dealers that in turn may sell such Shares.

prospectus supplement. Unless the applicable prospectus supplement states otherwise, our agent will act on a best-efforts basis for the period of some states,its appointment.

We may authorize agents, underwriters or dealers to solicit offers by certain types of institutional investors to purchase securities from us at the Shares may only be soldpublic offering price set forth in such states through registered or licensed brokers or dealers. In addition, in some states the Shares may not be sold unless such Shares have been registered or qualified for sale in such state or an exemption from registration or qualification is available and is complied with.

There can be no assurance that the selling stockholder will sell any or all of the Shares registeredprospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the registration statement, of which this prospectus forms a part.

The selling stockholder and any other person participating in such distributionfuture. We will be subjectdescribe the conditions to applicable provisions of the Exchange Act,these contracts and the rules and regulations thereunder, including, without limitation, Regulation Mcommissions we must pay for solicitation of the Exchange Act, which may limit the timing of purchases and sales of any of the Shares by the selling stockholder and any other participating person. Regulation M may also restrict the ability of any person engagedthese contracts in the distribution of the Shares to engage in market-making activities with respect to our common stock. All of the foregoing may affect the marketability of our common stock and the ability of any person or entity to engage in market-making activities with respect to our common stock.prospectus supplement.

We will pay all expenses of the registration of the Shares pursuant to the registration statement of which this prospectus forms a part, including, without limitation, SEC filing feesmay provide agents, underwriters and expenses of compliancedealers with state securities or “blue sky” laws; provided, however, that the selling stockholder will pay all underwriting discounts and selling commissions, if any. We will indemnify the selling stockholder against liabilities, including some liabilities under the Securities Act, or the selling stockholder will be entitled to contribution. We may be indemnified by the selling stockholderindemnification against civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents, underwriters or dealers may arisemake with respect to these liabilities. Agents, underwriters and dealers, or their affiliates, may engage in transactions with, or perform services for, us in the ordinary course of business.

All securities we may offer, other than common stock, will be new issues of securities with no established trading market. Any underwriters may make a market in these securities, but will not be obligated to do so and may discontinue any market making at any time without notice. We cannot guarantee the liquidity of the trading markets for any securities.

Any underwriter may engage in over-allotment, stabilizing transactions, short-covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. Over-allotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum price. Syndicate-covering or other short-covering transactions involve purchases of the securities, either through exercise of the over-allotment option or in the open market after the distribution is completed, to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from any written information furnished to usa dealer when the securities originally sold by the selling stockholder specificallydealer are purchased in a stabilizing or covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

Any underwriters or agents that are qualified market makers on the Nasdaq Global Market may engage in passive market making transactions in the common stock on the Nasdaq Global Market in accordance with Regulation M under the Exchange Act, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the common stock. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for usesuch security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

In compliance with guidelines of the Financial Industry Regulatory Authority, or FINRA, the maximum consideration or discount to be received by any FINRA member or independent broker dealer may not exceed 8% of the aggregate amount of the securities offered pursuant to this prospectus or we may be entitled to contribution.and the applicable prospectus supplement.

Once sold under the registration statement of which this prospectus forms a part, the Shares will be freely tradable in the hands of persons other than our affiliates.

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LEGAL MATTERS

Cooley LLP Chicago, Illinois, will pass upon the validity of the Sharessecurities offered hereby.by this prospectus, and any supplement thereto, unless otherwise indicated in the applicable prospectus supplement. 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 consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2021,2022, 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 ADDITIONAL INFORMATION

This prospectus is part of the registration statement on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus for a copy of such contract, agreement or other document. Because we are subject to the information and reporting requirements of the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov.

We In addition, we maintain a website that contains information about us at www.rapt.com. We do not incorporate theThe information containedfound on, or otherwise accessible through our website is not incorporated by reference into, this prospectus, and you shoulddoes not consider itform a part of, this prospectus. Our website address is included in this prospectus as an inactive textual reference only.or any accompanying prospectus supplement or any other document or report we file or furnish with the SEC.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus, while information that we file later with the SEC will automatically update and supersede the information in this prospectus. We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-38997):

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The information in this preliminary prospectus is not complete and may be changed. These securities may not be sold until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell nor does it seek an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED AUGUST 11, 2023

PROSPECTUS

Up to $150,000,000

Common Stock

We have entered into a Controlled Equity Offering^SM Sales Agreement, or the sales agreement, with Cantor Fitzgerald & Co., or Cantor, and Leerink Partners LLC, or Leerink Partners, relating to shares of our common stock, $0.0001 par value per share, offered by this prospectus. The controlling provisions of the sales agreement will become effective immediately upon the effectiveness of the registration statement of which this prospectus is a part. In accordance with the terms of the sales agreement, we may offer and sell shares of our common stock having an aggregate offering price of up to $150,000,000 from time to time through Cantor and Leerink Partners, acting as our sales agents. As of immediately prior to the filing date of this prospectus, shares of our common stock having an aggregate offering price of up to $85,717,806 remained unsold under the Controlled Equity Offering^SM Sales Agreement dated November 4, 2020, or the prior sales agreement, that we entered into with Cantor and Stifel, Nicolaus & Company, Incorporated and the sales agreement prospectus dated November 16, 2020, or the prior prospectus. The common stock remaining available to be sold under the prior prospectus as of the date of effectiveness of the registration statement of which this prospectus is a part will no longer be offered and sold under the prior prospectus and will instead be offered and sold under this prospectus. Accordingly, this prospectus covers the offer and sale of our common stock having an aggregate offering price of up to $150,000,000 to be sold under the sales agreement as of the date of this prospectus.

Our common stock is listed on the Nasdaq Global Market under the trading symbol “RAPT.” On August 9, 2023, the last reported sale price of our common stock was $24.05 per share.

Sales of our common stock, if any, under this prospectus may be made in sales deemed to be an “at-the-market” offering as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended, or the Securities Act. Subject to the terms of the sales agreement, Cantor and Leerink Partners are not required to sell any specific number or dollar amounts of securities but will act as sales agents and use commercially reasonable efforts to sell on our behalf all of the shares of common stock requested to be sold by us, consistent with their normal trading and sales practices, on mutually agreed terms between Cantor, Leerink Partners and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

Cantor and Leerink Partners will be entitled to compensation at a commission of up to 3.0% of the aggregate gross sales price per share sold by such sales agent under the sales agreement. See “Plan of Distribution” beginning on page 19 of this prospectus for additional information regarding Cantor and Leerink Partners’s compensation. In connection with the sale of our common stock on our behalf, Cantor and Leerink Partners may be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Cantor and Leerink Partners may be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contributions to Cantor and Leerink Partners against certain civil liabilities, including liabilities under the Securities Act.

We are an “emerging growth company” under the federal securities laws and are subject to reduced public company reporting requirements.

Investing in our common stock involves a high degree of risk. Before making an investment decision, you should review carefully and consider all of the information set forth in this prospectus and the documents incorporated by reference in this prospectus. See “Risk Factors” beginning on page 7 of this prospectus and in the documents incorporated by reference into this prospectus.

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                 , 2023.

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we have filed with the Securities and Exchange Commission, or SEC, using a “shelf” registration process. Under the shelf registration statement we may offer shares of our common stock, preferred stock, debt securities and warrants, including common stock or preferred stock upon conversion of debt securities, common stock upon conversion of preferred stock, or common stock, preferred stock or debt securities upon the exercise of warrants, having an aggregate offering price of up to a total dollar amount of $450,000,000. Under this prospectus, we may offer shares of our common stock having an aggregate offering price of up to $150,000,000 from time to time under this prospectus at prices and on terms to be determined by market conditions at the time of offering.

This prospectus describes the terms of this offering of shares of our common stock and also adds to and updates information contained in the documents incorporated by reference into this prospectus. To the extent there is a conflict between the information contained in this prospectus, on the one hand, and the information contained in any document incorporated by reference into this prospectus that was filed with the SEC before the date of this prospectus, on the other hand, you should rely on the information in this prospectus. If any statement in one of these documents is inconsistent with a statement in another document having a later date (for example, a document incorporated by reference into this prospectus), the statement in the document having the later date modifies or supersedes the earlier statement.

We have not, and Cantor and Leerink Partners have not, authorized any other person to provide you with any information or to make any representations other than those contained in or incorporated by reference into this prospectus, any prospectus supplement relating to this offering or in any free writing prospectuses prepared by or on behalf of us or to which we have referred you. We, Cantor and Leerink Partners take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We are not, and Cantor and Leerink Partners are not, making an offer to sell or soliciting an offer to buy our securities in any jurisdiction in which an offer or solicitation is not authorized or in which the person making that offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation. You should assume that the information appearing in this prospectus, any prospectus supplement relating to this offering, the documents incorporated by reference into this prospectus, and in any free writing prospectuses that we may authorize for use in connection with this offering, is accurate only as of the date of those respective documents. Our business, financial condition, results of operations and prospects may have changed since those dates. You should read this prospectus, any applicable prospectus supplement, the documents incorporated by reference into this prospectus, and any free writing prospectuses that we may authorize for use in connection with this offering, in their entirety before making an investment decision. You should also read and consider the information in the documents to which we have referred you in the sections of this prospectus captioned “Where You Can Find Additional Information” and “Incorporation of Certain Information by Reference.”

We are offering to sell, and seeking offers to buy, shares of common stock only in jurisdictions where offers and sales are permitted. The distribution of this prospectus and the offering of our common stock in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of our common stock and the distribution of this prospectus outside the United States. This prospectus does not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

We obtained the industry and market data in this prospectus, including the information incorporated by reference herein, from our own research as well as from industry and general publications, surveys and studies conducted by third parties. These data involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the industry in which we operate is necessarily subject to a high degree of

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uncertainty and risk due to a variety of factors, including those described in “Risk Factors” and elsewhere in this prospectus and information incorporated by reference herein. These and other factors could cause results to differ materially from those expressed in the estimates made by the independent parties and by us.

This prospectus, including the information incorporated by reference into this prospectus, include trademarks, service marks and trade names owned by us or others. All trademarks, service marks and trade names included or incorporated by reference in this prospectus or any related free writing prospectuses are the property of their respective owners.

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RISK FACTORS

Investing in our common stock involves a high degree of risk. Before deciding whether to invest in our common stock, you should consider carefully the risks and uncertainties described below and discussed under the heading “Risk Factors” contained in our most recent Annual Report on Form 10-K, and in our subsequent Quarterly Reports on Form 10-Q, as well as any amendments thereto reflected in subsequent filings with the SEC, which are incorporated by reference into this prospectus in their entirety, together with other information in this prospectus, any related prospectus supplement, the documents incorporated by reference and any free writing prospectuses that we may authorize for use in connection with this offering. The risks described in these documents are not the only ones we face, but those that we consider to be material. There may be other unknown or unpredictable economic, business, competitive, regulatory or other factors that could have material adverse effects on our future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. 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 common stock to decline, resulting in a loss of all or part of your investment. Please also read carefully the section below entitled “Special Note Regarding Forward-Looking Statements.”

Risks Related to This Offering

Management will have broad discretion as to the use of the proceeds from this offering, and may not use the proceeds effectively.

Because we have not designated the amount of net proceeds from this offering to be used for any particular purpose, our management will have broad discretion as to the application of the net proceeds from this offering and could use them for purposes other than those contemplated at the time of the offering. Our management may use the net proceeds for corporate purposes that may not improve our financial condition or market value.

You may experience immediate and substantial dilution as a result of this offering.

The offering price per share of our common stock in this offering may exceed the net tangible book value per share of our common stock outstanding prior to this offering. Assuming that 6,237,006 shares of our common stock are sold in this offering, based on an assumed sale price of $24.05 per share, the last sale price of a share of our common stock on the Nasdaq Global Market on August 9, 2023, for aggregate gross proceeds of $150.0 million, and after deducting commissions and estimated offering expense payable by us, you would experience immediate dilution, representing the difference between the price you pay and our as adjusted net tangible book value per share as of June 30, 2023, after giving effect to this offering, of $15.56 per share. The exercise of outstanding stock options, pre-funded warrants and vesting of restricted stock units may result in further dilution of your investment. See the section titled “Dilution” below for a more detailed illustration of the dilution you would incur if you participate in this offering.

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

To raise additional capital, we may in the future offer additional shares of our common stock or other securities convertible into or exchangeable for our common stock at prices that may not be the same as the price 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 our common stock, or securities convertible or exchangeable into 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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Sales of a substantial number of shares of our common stock in the public market could cause our stock price to fall.

Sales of a substantial number of shares of our common stock in the public market could occur at any time. These sales, or the perception in the market that the holders of a large number of shares intend to sell shares, could reduce the market price of our common stock. Moreover, certain holders of our common stock have rights, subject to certain conditions, to require us to file registration statements covering their shares or to include their shares in registration statements that we may file for ourselves or other stockholders.

We do not intend to pay dividends in the foreseeable future.

We have never paid cash dividends on our common stock and currently do not plan to pay any cash dividends in the foreseeable future.

It is not possible to predict the aggregate proceeds resulting from sales made under the sales agreement.

Subject to certain limitations in the sales agreement and compliance with applicable law, we have the discretion to deliver a placement notice to Cantor and Leerink Partners, at any time throughout the term of the sales agreement. The number of shares that are sold through Cantor and Leerink Partners after delivering a placement notice will fluctuate based on a number of factors, including the market price of our common stock during the sales period, any limits we may set with Cantor and Leerink Partners in any applicable placement notice and the demand for our common stock. Because the price per share of each share sold pursuant to the sales agreement will fluctuate over time, it is not currently possible to predict the aggregate proceeds to be raised in connection with sales under the sales agreement.

Sales of common stock offered hereby will be in “at the market offerings,” and investors who buy shares at different times will likely pay different prices.

Investors who purchase shares in this offering at different times will likely pay different prices, and accordingly may experience different levels of dilution and different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing, prices and number of shares sold in this offering. In addition, subject to the final determination by our board of directors or any restrictions we may place in any applicable placement notice delivered to Cantor and Leerink Partners, there is no minimum or maximum sales price for shares to be sold in this offering. Investors may experience a decline in the value of the shares they purchase in this offering as a result of sales made at prices lower than the prices they paid.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents we have filed with the SEC that are incorporated by reference in this prospectus contain “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 Securities Exchange Act of 1934, or the Exchange Act. These statements relate to future events or to our future operating or financial performance and involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Forward-looking statements may include, but are not limited to, statements about:

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In some cases, you can identify forward-looking statements by terms such as “anticipates,” “believes,” “could,” “estimates,” “expects,” “may,” “plans,” “potential” “predicts,” “projects,” “should,” “will,” “would,” and similar expressions intended to identify forward-looking statements. These statements reflect our current views with respect to future events and are based on assumptions and are subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. We discuss in greater detail many of these risks under the heading “Risk Factors” contained in this prospectus, and in our most recent Annual Report on Form 10-K and in our most recent Quarterly Report on Form 10-Q, as well as any amendments thereto reflected in subsequent filings with the SEC, which are incorporated by reference into this prospectus in their entirety. Also, these forward-looking statements represent our estimates and assumptions only as of the date of the document containing the applicable statement. Unless required by law, we undertake no obligation to update or revise any forward-looking statements to reflect new information or future events or developments. Thus, you should not assume that our silence over time means that actual events are bearing out as expressed or implied in such forward-looking statements. You should read this prospectus, any applicable prospectus supplement, together with the documents we have filed with the SEC that are incorporated by reference and any free writing prospectuses that we may authorize for use in connection with this offering completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of the forward-looking statements in the foregoing documents by these cautionary statements.

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USE OF PROCEEDS

We may issue and sell shares of our common stock having aggregate sales proceeds of up to $150,000,000 from time to time. Because there is no minimum offering amount required pursuant to the sales agreement, with Cantor and Leerink Partners, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. Actual net proceeds will depend on the number of shares we sell and the prices at which such sales occur. There can be no assurance that we will sell any shares under or fully utilize the sales agreement with Cantor and Leerink Partners as a source of financing.

We intend to use the net proceeds from this offering, if any, for working capital, capital expenditures and other general corporate purposes, including research and development expenses.

The amounts and timing of our use of the net proceeds from this offering will depend on a number of factors, such as the timing and progress of our research and development efforts, the timing and progress of any partnering and commercialization efforts, technological advances and the competitive environment for our products. As of the date of this prospectus, we cannot specify with certainty all of the particular uses for the net proceeds to us from the sale of the securities offered by us hereunder. Accordingly, our management will have broad discretion in the timing and application of these proceeds. Pending application of the net proceeds as described above, we intend to temporarily invest the proceeds in short-term, interest-bearing instruments.

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DILUTION

If you purchase common stock in this offering, your ownership interest will be diluted to the extent of the difference between the purchase price per share and the as adjusted net tangible book value per share after giving effect to this offering. We calculate net tangible book value per share by dividing the net tangible book value, which is tangible assets less total liabilities, by the number of outstanding shares of our common stock. Dilution represents the difference between the portion of the amount per share paid by purchasers of shares in this offering and the as adjusted net tangible book value per share of our common stock immediately after giving effect to this offering. Our net tangible book value as of June 30, 2023, was approximately $199.7 million, or $5.81 per share.

After giving effect to the assumed sale of 6,237,006 shares of our common stock by us in this offering at an assumed public offering price of $24.05 per share, the last sale price of our common stock on the Nasdaq Global Market on August 9, 2023, after deducting commissions and estimated aggregate offering expenses payable by us, our as adjusted net tangible book value as of June 30, 2023, would have been $344.7 million, or $8.49 per share of common stock. This represents an immediate increase in the as adjusted net tangible book value of $2.68 per share to our existing stockholders and an immediate dilution of $15.56 per share to new investors purchasing shares in this offering. The following table illustrates this per share dilution:

In addition, the foregoing does not include up to $85,717,806 of our common stock that remained available for sale at June 30, 2023 under the prior sales agreement and prior prospectus, which may continue to be offered and sold until the effectiveness of the registration statement of which this prospectus forms a part.

To the extent that any outstanding options are exercised, pre-funded warrants are exercised, restricted stock units vest or common stock is sold pursuant to the sales agreement and the prior prospectus prior to the effectiveness of the registration statement of which this prospectus forms a part, there could be 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 additional capital is raised 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 500,000,000 shares of common stock, $0.0001 par value per share, and 50,000,000 shares of preferred stock, $0.0001 par value per share. A description of material terms and provisions of our amended and restated certificate of incorporation, or the Certificate of Incorporation, amended and restated bylaws, or the bylaws, and applicable provisions of the General Law of the State of Delaware, or the DGCL, affecting the rights of holders of our capital stock is set forth below. The description is intended as a summary, and is qualified in its entirety by reference to our Certificate of Incorporation, our bylaws and the DGCL.

Common Stock

Voting Rights. Each holder of common stock is entitled to one vote for each share of common stock held on all matters submitted to a vote of the stockholders, including the election of directors. The Certificate of Incorporation and bylaws do not provide for cumulative voting rights in connection with election of directors unless, at the time of such election, we are subject to Section 2115(b) of the California General Corporation Law. The affirmative vote of holders of 66 2/3% of the voting power of all of the then-outstanding shares of capital stock, voting as a single class, will be required to amend certain provisions of our Certificate of Incorporation, including provisions relating to amending our bylaws, and removal of directors.

Dividends. Subject to preferences that may be applicable to any then outstanding preferred stock, the holders of outstanding shares of common stock may receive dividends, if any, as may be declared from time to time by the board of directors out of legally available funds. We have never issued a dividend on shares of our common stock and we have no intention to do so in the future.

Liquidation. In the event we liquidate, dissolve or wind up, the assets legally available for distribution shall be distributed ratably to the holders of shares of common stock and preferred stock, after payment of liabilities, subject to the satisfaction of any liquidation preference granted to the holders of any outstanding shares of preferred stock.

Rights and Preferences. Holders of common stock have no preemptive, conversion or subscription rights, and there are no redemption or sinking fund provisions applicable to the common stock. The rights, preferences and privileges of the holders of 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.

Fully Paid and Nonassessable. All outstanding shares of common stock are fully paid and nonassessable.

Preferred Stock

Our board of directors is authorized, subject to limitations prescribed by Delaware law, to issue up to 50,000,000 shares of preferred stock in one or more series, to establish from time to time the number of shares to be included in each series and to fix the designation, powers, preferences and rights of the shares of each series and any of its qualifications, limitations or restrictions. Our board of directors can also increase or decrease the number of shares of any series, but not below the number of shares of that series then outstanding, without any further vote or action by the company’s stockholders. 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 the common stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring, discouraging or preventing a change in control of RAPT and may adversely affect the market price of RAPT’s common stock and the voting and other rights of the holders of common stock.

Our board of directors will fix the designations, voting powers, preferences and rights of the preferred stock of each series we issue under this prospectus, as well as the qualifications, limitations or restrictions thereof, in the

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certificate of designation relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of any certificate of designation that contains the terms of the series of preferred stock we are offering. We will describe in the applicable prospectus supplement the terms of the series of preferred stock being offered, including, to the extent applicable:

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Registration Rights

We are party to an amended and restated investor rights agreement that provides certain registration rights to certain holders of our common stock. The requisite holders of registrable securities pursuant to the registration rights agreement have waived their registration rights in connection with the filing of the registration statement of which this prospectus forms a part and any offering of securities pursuant to such registration statement.

Anti-Takeover Effects of Provisions of Our Certificate of Incorporation, Bylaws and Delaware Law

Certificate of incorporation and bylaws. Our Certificate of Incorporation and bylaws include a number of provisions that may deter or impede hostile takeovers or changes of control or management. These provisions include:

We designed these provisions to enhance the likelihood of continued stability in the composition of our board of directors and its policies, to discourage certain types of transactions that may involve an actual or threatened acquisition of us, and to reduce our vulnerability to an unsolicited acquisition proposal. We also designed these provisions to discourage certain tactics that may be used in proxy fights. However, these provisions could have the effect of discouraging others from making tender offers for our shares and, as a consequence, they may also reduce fluctuations in the market price of our shares that could result from actual or rumored takeover attempts.

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Section 203 of the Delaware General Corporation Law

We are subject to Section 203 of the DGCL, which prohibits a Delaware corporation from engaging in a business combination with any interested stockholder for a period of three years following the date the person became an interested stockholder, with the following exceptions:

In general, Section 203 of the DGCL defines business combination to include the following:

Section 203 of the DGCL defines an “interested stockholder” as an entity or person who, together with the entity’s or person’s affiliates and associates, beneficially owns, or is an affiliate of the corporation and within three years prior to the time of determination of interested stockholder status did own, 15% or more of the outstanding voting stock of the corporation. A Delaware corporation may “opt out” of these provisions with an express provision in its certificate of incorporation. We have not opted out of these provisions, which may as a result, discourage or prevent mergers or other takeover or change of control attempts of us.

Choice of Forum

Our Certificate of Incorporation provides that the Court of Chancery of the State of Delaware will be the exclusive forum for the following types of actions or proceedings under Delaware statutory or common law: (i) any derivative action or proceeding brought on our behalf; (ii) any action asserting a claim of breach of a fiduciary duty owed by any director, officer or other employee of our company to us or our stockholders; (iii) any action asserting a claim against us or any director or officer or other employee of our company arising pursuant to the General Corporation Law of the State of Delaware, our Certificate of Incorporation or bylaws; or (iv) any action asserting a claim against us or any director or officer or other employee of our company that is governed by the internal affairs doctrine. This provision would not apply to claims brought to enforce a duty or liability created by the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction. Our Certificate of Incorporation further provides that the federal district courts of the United States of America will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act.

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Transfer Agent and Registrar

Our transfer agent and registrar for our common stock is Equinti Trust Company, LLC. The transfer agent for any series of preferred stock that we may offer under this prospectus will be named and described in the applicable prospectus supplement related to that series.

Listing on the Nasdaq Global Market

Our common stock is listed on the Nasdaq Global Market the symbol “RAPT.” 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 exchange of the preferred stock covered by such prospectus supplement.

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PLAN OF DISTRIBUTION

We have entered into the sales agreement with Cantor and Leerink Partners relating to shares of our common stock, $0.0001 par value per share, offered by this prospectus. The controlling provisions of the sales agreement will become effective immediately upon the effectiveness of the registration statement of which this prospectus is a part. In accordance with the terms of the sales agreement, we may offer and sell shares of our common stock having an aggregate offering price of up to $150,000,000 from time to time through Cantor and Leerink Partners, acting as our sales agents. As of immediately prior to the filing date of this prospectus, shares of our common stock having an aggregate offering price of up to $85,717,806 remained unsold under the prior sales agreement and the prior prospectus. The common stock remaining available to be sold under the prior prospectus as of the date of effectiveness of the registration statement of which this prospectus is a part will no longer be offered and sold under the prior prospectus and will instead be offered and sold under this prospectus. Accordingly, this prospectus covers the offer and sale of our common stock having an aggregate offering price of up to $150,000,000 to be sold under the sales agreement as of the date of this prospectus. The sales agreement has been filed as an exhibit to our Registration Statement on Form S-3 of which this prospectus forms a part.

We will submit orders to only one sales agent relating to the sale of shares of our common stock under the sales agreement on any given day. Upon delivery of a placement notice to a sales agent and subject to the terms and conditions of the sales agreement, such sales agent may offer and sell shares of our common stock by any method permitted by law deemed to be an “at the market offering,” as defined in Rule 415(a)(4) promulgated under the Securities Act. We may instruct such sales agent not to sell common stock if the sales cannot be effected at or above the price designated by us from time to time. We or the sales agents may suspend the offering of common stock upon notice and subject to other conditions.

We will pay the sales agents commissions for their services in acting as agent in the sale of our common stock. A sales agent is entitled to compensation at a commission rate of up to 3.0% of the gross sales price per share sold by such sales agent under the sales agreement. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. We have also agreed to reimburse the sales agents for certain specified fees and documented expenses, including the fees and documented expenses of their legal counsel in an amount not to exceed $75,000, as provided in the sales agreement. We estimate that the total expenses for the offering, excluding compensation and reimbursements, if any, payable to Cantor and Leerink Partners under the terms of the sales agreement, will be approximately $500,000.

Settlement for sales of shares of common stock will occur on the second business day following the date on which any sales are made, or on some other date that is agreed upon by us and the applicable sales agent in connection with a particular transaction, in return for payment of the net proceeds to us. Sales of our common stock as contemplated in this prospectus will be settled through the facilities of The Depository Trust Company or by such other means as we and the applicable sales agents may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

The sales agents will use their commercially reasonable efforts, consistent with their sales and trading practices, to solicit offers to purchase the shares of common stock under the terms and subject to the conditions set forth in the sales agreement. In connection with the sale of the shares of common stock on our behalf, the applicable sales agent may be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation of such sales agent (and their respective partners, members, directors, officers, employees and agents) may be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to each sales agent against certain liabilities, including civil liabilities under the Securities Act.

The offering of shares of our common stock pursuant to the sales agreement will terminate upon the termination of the sales agreement as permitted therein. Either sales agent may terminate the sales agreement, with respect to such sales agent’s rights and obligations under the sales agreement, at any time upon ten days’ prior notice. We

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may terminate the sales agreement with respect to either or both sales agents at any time upon ten days’ prior notice.

This summary of the material provisions of the sales agreement does not purport to be a complete statement of its terms and conditions. A copy of the sales agreement has been filed as an exhibit to our Registration Statement on Form S-3 of which this prospectus forms a part.

The sales agents and their respective affiliates may in the future provide various investment banking, commercial banking and other financial services for us, our subsidiaries and our affiliates, for which services they may in the future receive customary fees. To the extent required by Regulation M, the sales agents will not engage in any market-making activities involving our common stock while the offering is ongoing under this prospectus. This prospectus in electronic format may be made available on a website maintained by Cantor or Leerink Partners, and each of Cantor and Leerink Partners may distribute this prospectus electronically.

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LEGAL MATTERS

Cooley LLP has passed upon the validity of the shares of our common stock offered hereby. The sales agents are being represented by Davis Polk & Wardwell LLP, in connection with the offering.

EXPERTS

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2022, 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 ADDITIONAL INFORMATION

This prospectus is part of the registration statement on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus for a copy of such contract, agreement or other document. Because we are subject to the information and reporting requirements of the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. In addition, we maintain a website that contains information about us at www.rapt.com. The information found on, or otherwise accessible through our website is not incorporated by reference into, and does not form a part of, this prospectus or any accompanying prospectus supplement or any other document or report we file or furnish with the SEC.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference information from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus, while information that we file later with the SEC will automatically update and supersede the information in this prospectus. We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC (Commission File No. 001-38997):

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We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including those made after the date of the initial filing of the registration statement of which this prospectus is a part and prior to effectiveness of such registration statement, until we file a post-effective amendment that indicates the termination of the offering of the securities made by this prospectus, which will become a part of this prospectus from the date that such documents are filed with the SEC. Information in such future filings updates and supplements the information provided in this prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later-filed document modify or replace such earlier statements. We will furnish without charge to each person, including any beneficial owner, to whom a prospectus is delivered, upon written or oral request, a copy of any or all of the documents incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits that are specifically incorporated by reference into such documents. You should direct any requests for documents to:

RAPT Therapeutics, Inc.

Attn: Chief Financial Officer

561 Eccles Avenue

South San Francisco, California 94080

(650) 489-9000

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4,000,000 shares

Up to $150,000,000

Common stockStock

PRELIMINARY PROSPECTUS

        , 2023

PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

The following table sets forth an estimate of the variousfees and expenses, to be incurredother than the underwriting discounts and commissions, payable by the registrant in connection with the saleissuance and distribution of the securities being registered hereby, all of which will be borne by RAPT Therapeutics, Inc. (the “Company”) (except any underwriting discounts and commissions and expenses incurred byregistered. All the selling stockholder for brokerage, accounting or tax services or any other expenses incurred by the selling stockholder in disposing of the shares). All amounts shown are estimates, except for the SEC registration fee.

RAPT has entered, and intends to continue to enter, into separate indemnification agreements with its directors and executive officers to provide these directors and executive officers additional contractual

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Item 16. Exhibits

EXHIBIT INDEX

Item 17. Undertakings

The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) to include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

(ii) to reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

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(5) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(6) That, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to sectionSection 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(7) That, for purposes of determining any liability under the Securities Act of 1933, (i) the information omitted from the form of prospectus filed as part of the registration statement in reliance upon Rule 430A and contained in the form of prospectus filed by the registrant pursuant to Rule 424(b)(l) or (4) or 497(h) under the Securities Act shall be deemed to be a part of the registration statement as of the time it was declared effective; and (ii) each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(6) (8) To file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the Commission under Section 305(b)(2) of the Trust Indenture Act.

Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act of 1933 and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of South San Francisco, State of California, on June 24, 2022.this 11th day of August, 2023.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Brian Wong, and Rodney Young and Michael Listgarten, and each of them, as true and lawful attorneys-in-fact and agents, with full powers of substitution and resubstitution, for them and in their name, place and stead, in any and all capacities, to sign any and all amendments (includingpre-effective and post-effective amendments) to this registration statement, and to sign any registration statement for the same offering covered by this registration statement that is to be effective upon filing pursuant to Rule 462 under the Securities Act of 1933, as amended, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission,SEC, and generally to do all such things in their names and behalf in their capacities as officers and directors to enable the RAPT Therapeutics, Inc. to comply with the provisions of the Securities Act of 1933 as amended, and all requirements of the Securities and Exchange Commission,SEC, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their or his substitutes or substitute, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.

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