Description of Securities

Exhibit 4.3

Revolution Medicines, Inc. (“we,” “us,” “our” and the “Company”) has two classes of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”): our common stock and public warrants. The following description of our common stock and warrants is a summary and does not purport to be complete. It is subject to and qualified in its entirety by reference to our amended and restated certificate of incorporation; our amended and restated bylaws; our amended and restated investors’ rights agreement to which we and certain of our stockholders are parties; the warrant-related documents described herein and the earn-out related documents described herein, each of which are incorporated by reference as exhibits to the Annual Report on Form 10-K, of which this exhibit is a part, and by applicable law. We encourage you to read our amended and restated certificate of incorporation; our amended and restated bylaws; our amended and restated investors’ rights agreement; the warrant-related documents described herein; the earn-out related documents described herein and the applicable provisions of Delaware law for more information.

Our authorized capital stock consists of 310,000,000 shares, consisting of 300,000,000 shares of common stock, $0.0001 par value, and 10,000,000 shares of preferred stock, $0.0001 par value.

Each holder of our common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. Our stockholders do not have cumulative voting rights in the election of directors. Accordingly, holders of a majority of the voting shares are able to elect all of the directors. In addition, the affirmative vote of holders of 66-2/3% of the voting power of all of the then outstanding voting stock is required to take certain actions, including amending certain provisions of our amended and restated certificate of incorporation, such as the provisions relating to amending our amended and restated bylaws, the classified board and director liability.

Subject to preferences that may be applicable to any then outstanding preferred stock, holders of our common stock are entitled to receive dividends, if any, as may be declared from time to time by our board of directors out of legally available funds.

In the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of our debts and other liabilities and the satisfaction of any liquidation preference granted to the holders of any then outstanding shares of preferred stock.

Holders of our common stock have no preemptive, conversion, subscription or other rights, and there are no redemption or sinking fund provisions applicable to our common stock. The rights, preferences and privileges of the holders of our common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of our preferred stock that we may designate in the future.

All of our outstanding shares of common stock are fully paid and nonassessable.

Each of our public warrants entitle the registered holder thereof to purchase 0.1112 shares of our common stock at an exercise price of $11.50 per such fractional share, subject to adjustment as discussed below. Pursuant to that certain Warrant Agreement, dated April 6, 2021, between EQRx and Continental Stock Transfer & Trust Company (the “Warrant Agreement”), a warrant holder may exercise its public warrants only for a whole number of shares of common stock. If, upon exercise of the public warrants, a holder would be entitled to receive a fractional interest in a share, we will, upon exercise, round down to the nearest whole number the number of shares of common stock to be issued to the warrant holder. The public warrants expire December 17, 2026, at 5:00 p.m., New York City time, or earlier upon redemption or liquidation.

We are not obligated to deliver any shares of common stock pursuant to the exercise of a public warrant and have no obligation to settle such public warrant exercise unless a registration statement under the Securities Act of 1933, as amended (the “Securities Act”) with respect to the shares of common stock underlying the public warrants is then effective and a prospectus relating thereto is current, subject to our satisfying our obligations described below with respect to registration. No public warrant will be exercisable for cash or on a cashless basis, and we will not be obligated to issue any shares to holders seeking to exercise their public warrants, unless the issuance of the shares upon such public warrant exercise is registered or qualified under the securities laws of the state of the exercising holder, or an exemption is available. In the event that the conditions in the two immediately preceding sentences are not satisfied with respect to a public warrant, the holder of such public warrant will not be entitled to exercise such public warrant and such public warrant may have no value and expire worthless.

During any period when we have failed to maintain an effective registration statement covering the shares of common stock issuable upon exercise of the public warrants, warrant holders have the right to exercise public warrants on a “cashless basis” in accordance with the provisions of the Warrant Agreement. Notwithstanding the above, if our common stock is at the time of any exercise of a public warrant not listed on a national securities exchange such that it satisfies the definition of a “covered security” under Section 18(b)(1) of the Securities Act, we may, at our option, require holders of public warrants who exercise their public warrants to do so on a “cashless basis” in accordance with Section 3(a)(9) of the Securities Act (or any successor rule).

Redemption of Warrants When the Price per Share of Common Stock Equals or Exceeds $161.87 — We may redeem the outstanding public warrants:

If and when the public warrants become redeemable, we may exercise our redemption right even if we are unable to register or qualify the underlying securities for sale under all applicable state securities laws.

Redemption of Warrants When the Price per Share of Common Stock Equals or Exceeds $89.93 — We may redeem the outstanding public warrants:

If the foregoing conditions are satisfied and we issue a notice of redemption of the public warrants, each warrant holder will be entitled to exercise its public warrant prior to the scheduled redemption date. However, the price of our common stock may fall below the $161.87 redemption trigger price as well as the warrant exercise price after the redemption notice is issued.

Redemption Procedures and Cashless Exercise. If we call the public warrants for redemption as described above, our management will have the option to require any holder that wishes to exercise its public warrant to do so on a “cashless basis.” In determining whether to require all holders to exercise their public warrants on a “cashless basis,” our management will consider, among other factors, its cash position, the number of public warrants that are outstanding and the dilutive effect on our stockholders of issuing the maximum number of shares of common stock issuable upon the exercise of the public warrants. If our management takes advantage of this option, all holders of public warrants would pay the exercise price by surrendering their public warrants for that number of shares of common stock equal to the quotient obtained by dividing (x) the product of the number of shares of common stock underlying the public warrants, multiplied by the difference between the exercise price of the public warrants and the “fair market value” (defined below) by (y) the fair market value. The “fair market value” means the average reported last sale price of our common stock for the ten trading days ending on the third trading day prior to the date on which the notice of redemption is sent to the holders of public warrants. If our management takes advantage of this option, the notice of redemption will contain the information necessary to calculate the number of shares of common stock to be received upon exercise of the public warrants, including the “fair market value” in such case. Requiring a cashless exercise in this manner will reduce the number of shares to be issued and thereby lessen the dilutive effect of a warrant redemption.

A holder of a public warrant may notify us in writing in the event it elects to be subject to a requirement that such holder will not have the right to exercise such public warrant, to the extent that after giving effect to such exercise, such person (together with such person’s affiliates), to the warrant agent’s actual knowledge, would beneficially own in excess of 4.9% or 9.8% (as specified by the holder) of the shares of our common stock outstanding immediately after giving effect to such exercise.

Anti-dilution Adjustments. If the number of outstanding shares of common stock is increased by a stock dividend payable in shares of common stock, or by a split-up of shares of common stock or other similar event, then, on the effective date of such stock dividend, split-up or similar event, the number of shares of common stock issuable on exercise of each public warrant will be increased in proportion to such increase in the outstanding shares of common stock. A rights offering to holders of common stock entitling holders to purchase shares of common stock at a price less than the fair market value (defined below) will be deemed a stock dividend of a number of shares of common stock equal to the product of (i) the number of shares of common stock actually sold in such rights offering (or issuable under any other equity securities sold in such rights offering that are convertible into or exercisable for common stock) and (ii) one (1) minus the quotient of (x) the price per share of common stock paid in such rights offering divided by (y) the fair market value. For these purposes, (i) if the rights offering is for securities convertible into or exercisable for common stock, in determining the price payable for common stock, there will be taken into account any consideration received for such rights, as well as any additional amount payable upon exercise or conversion and (ii) fair market value means the volume weighted average price of common stock as reported during the ten (10) trading day period ending on the trading day prior to the first date on which the shares of common stock trade on the applicable exchange or in the applicable market, regular way, without the right to receive such rights.

In addition, if we, at any time while the public warrants are outstanding and unexpired, pay a dividend or make a distribution in cash, securities or other assets to the holders of common stock on account of such shares of common stock (or other shares of our capital stock into which the public warrants are convertible), other than (a) as described above or (b) certain ordinary cash dividends, then the public warrant exercise price will be decreased, effective immediately after the effective date of such event, by the amount of cash and/or the fair market value as determined by our board of directors in good faith of any securities or other assets paid on each share of common stock in respect of such event.

If the number of outstanding shares of our common stock is decreased by a consolidation, combination, reverse stock split or reclassification of shares of common stock or other similar event, then, on the effective date of such consolidation, combination, reverse stock split, reclassification or similar event, the number of shares of common stock issuable on exercise of each public warrant will be decreased in proportion to such decrease in outstanding shares of common stock.

Whenever the number of shares of common stock purchasable upon the exercise of the warrants is adjusted, as described above, the public warrant exercise price will be adjusted (to the nearest cent) by multiplying the warrant exercise price immediately prior to such adjustment by a fraction (x) the numerator of which will be the number of shares of common stock purchasable upon the exercise of the public warrants immediately prior to such adjustment, and (y) the denominator of which will be the number of shares of common stock so purchasable immediately thereafter.

In case of any reclassification or reorganization of the outstanding shares of common stock (other than those described above or that solely affects the par value of such shares of common stock), or in the case of any merger or consolidation of us with or into another corporation (other than a consolidation or merger in which we are the continuing corporation and that does not result in any reclassification or reorganization of the outstanding shares of our common stock), or in the case of any sale or conveyance to another corporation or entity of the assets or other property of us as an entirety or substantially as an entirety in connection with which we are dissolved, the holders of the public warrants will thereafter have the right to purchase and receive, upon the basis and upon the terms and conditions specified in the public warrants and in lieu of the shares of our common stock immediately theretofore purchasable and receivable upon the exercise of the rights represented thereby, the kind and amount of shares of stock or other securities or property (including cash) receivable upon such reclassification, reorganization, merger or consolidation, or upon a dissolution following any such sale or transfer, that the holder of the public warrants would have received if such holder had exercised their public warrants immediately prior to such event. However, if such holders were entitled to exercise a right of election as to the kind or amount of securities, cash or other assets receivable upon such consolidation or merger, then the kind and amount of securities, cash or other assets for which each public warrant will become exercisable will be deemed to be the weighted average of the kind and amount received per share by such holders in such consolidation or merger that affirmatively make such election, and if a tender, exchange or redemption offer has been made to and accepted by such holders (other than a tender, exchange or redemption offer made by us in connection with redemption rights held by our stockholders) under circumstances in which, upon completion of such tender or exchange offer, the maker thereof, together with members of any group (within the meaning of Rule 13d-5(b)(1) under the Exchange Act (or any successor rule)) of which such maker is a part, and together with any affiliate or associate of such maker (within the meaning of Rule 12b-2 under the Exchange Act (or any successor rule)) and any members of any such group of which any such affiliate or associate is a part, own beneficially (within the meaning of Rule 13d-3 under the Exchange Act (or any successor rule)) more than 50% of the outstanding shares of common stock, the holder of a public warrant will be entitled to receive the highest amount of cash, securities or other property to which such holder would actually have been entitled as a stockholder if such warrant holder had exercised the public warrant prior to the expiration of such tender or exchange offer, accepted such offer and all of the common stock held by such holder had been purchased pursuant to such tender or exchange offer, subject to adjustments (from and after the consummation of such tender or exchange offer) as nearly equivalent as possible to the adjustments provided for in the Warrant Agreement. Additionally, if less than 70% of the consideration receivable by the holders of common stock in such a transaction is payable in the form of common stock in the successor entity that is listed for trading on a national securities exchange or is quoted in an established over-the-counter market, or is to be so listed for trading or quoted immediately following such event, and if the registered holder of the public warrant properly exercises the public warrant within thirty days following public disclosure of the consummation of such applicable event by us pursuant to a Current Report on Form 8-K filed with the Securities and Exchange Commission, the public warrant exercise

price will be reduced as specified in the Warrant Agreement based on the per share consideration minus Black-Scholes warrant value (as defined in the Warrant Agreement) of the public warrant.

The public warrants were issued in registered form under the Warrant Agreement between Continental Stock Transfer & Trust Company, as warrant agent, and EQRx. On November 9, 2023, the public warrants became securities of the Company and Equiniti Trust Company, LLC became the warrant agent. You should review a copy of the Warrant Agreement, which is incorporated by reference as an exhibit to Annual Report on Form 10-K to which this Exhibit 4.3 is filed as an exhibit, for a complete description of the terms and conditions applicable to the public warrants. The Warrant Agreement provides that the terms of the public warrants may be amended without the consent of any holder to cure any ambiguity or correct any defective provision, but requires the vote or written consent by the holders of at least 50% of the then-outstanding public warrants to make any change that adversely affects the interests of the registered holders of public warrants.

The public warrants may be exercised upon surrender of the warrant certificate on or prior to the expiration date at the offices of the warrant agent (which is currently Equiniti Trust Company, LLC), with the exercise form on the reverse side of the warrant certificate completed and executed as indicated, accompanied by full payment of the exercise price (or on a cashless basis, if applicable), by good certified check, good bank draft or by wire of immediately available funds, for the number of public warrants being exercised. The warrant holders do not have the rights or privileges of holders of common stock until they exercise their public warrants and receive shares of common stock. After the issuance of shares of common stock upon exercise of the public warrants, each holder will be entitled to one vote for each share held of record on all matters to be voted on by stockholders.

Each of our private warrants entitle the registered holder thereof to purchase 0.1112 shares of our common stock at an exercise price of $11.50 per such fractional share, subject to adjustment. If, upon exercise of the private warrants, a holder would be entitled to receive a fractional interest in a share, we will, upon exercise, round down to the nearest whole number the number of shares of common stock to be issued to the warrant holder. The terms of the private warrants are substantially the same as to the public warrants; provided, that, except as described above in the discussion of the redemption of public warrants when the price per share of our common stock equals or exceeds $89.93, the private warrants are exercisable on a cashless basis and are non-redeemable for cash so long as they are held by the initial purchasers or their permitted transferees. If the private warrants are held by someone other than the initial purchasers or their permitted transferees, the private warrants are redeemable by the Company and exercisable by such holders on the same basis as the public warrants.

There are 5,560,000 earn-out shares (the “Earn-Out Shares”) of common stock outstanding and held in escrow that may become tradeable upon the achievement of certain stock price-based vesting conditions in accordance with the terms of the Agreement and Plan of Merger dated August 5, 2021, by and among EQRx, Inc. (f/k/a CM Life Sciences III Inc.), Clover III Merger Sub Inc. and EQRx International, Inc. (f/k/a EQRx, Inc.) and certain ancillary agreements related to the Earn-Out Shares; however, persons with rights to approximately 82% of the Earn-Out Shares have signed and delivered waiver and release agreements to us pursuant to which, among other things, they have waived their respective rights to receive any such Earn-Out Shares to which they may have been entitled upon the occurrence of any vesting condition described below.

Seventy percent of the Earn-Out Shares will vest and be released from escrow (if ever) on the date on which the closing price of our common stock equals or exceeds $112.41 on any 20 trading days in any 30 consecutive trading-day period, and the remaining 30% of Earn-Out Shares will vest and be released from escrow (if ever) on the date on which the closing price of our common stock equals or exceeds $148.38 on any 20 trading days in any 30 consecutive trading-day period, in each case provided such vesting occurs prior to December 17, 2024, provided, that in the event that certain change in control events occur prior to December 17, 2024 pursuant to which we or any of our stockholders have the right to receive, directly or indirectly, cash, securities or other property attributing a value of at least $112.41 (with respect to 70% of the Earn-Out Shares) or $148.38 (with respect to the remaining 30% of the Earn-Out Shares) per share of common stock, then such Earn-Out Shares, as applicable, shall be deemed to have vested immediately prior to such change in control event and will subsequently be released from escrow. Earn-Out Shares are issued and outstanding and will be automatically forfeited for no consideration if an applicable

vesting condition has not occurred with respect to such Earn-Out Shares by and including December 17, 2024. The Earn-Out Shares generally may not be transferred until the applicable vesting conditions have occurred.

Under our amended and restated investors’ rights agreement, certain holders of shares of our common stock, or their transferees, have the right to require us to register their shares under the Securities Act so that those shares may be publicly resold, those holders, or their transferees, have the right to include their shares in any registration statement we file, in each case as described below. The shares subject to such registration rights are referred to as registrable securities.

Holders of registrable securities are entitled to certain Form S-1 demand registration rights.

Beginning on August 11, 2020, the holders of at least a majority of the registrable securities can request that we register all or a portion of their shares, so long as such holders request that we register at least 40% of the registrable securities. These stockholders may make up to two requests for registration on Form S-1.

Holders of registrable securities are entitled to certain Form S-3 demand registration rights. If we are eligible to use a Form S-3 registration statement, the holders of at least 20% of the registrable securities can request that we register all or a portion of their shares on a Form S-3 registration statement if the anticipated aggregate offering price is at least $5.0 million, net of certain expenses related to the sale of the shares. These stockholders may make unlimited requests for registration on Form S-3, provided that we are not obligated to effect, or take any action to effect, a registration on Form S-3 if we have effected two registrations on Form S-3 pursuant to requests by these stockholders within the 12-month period immediately preceding such request.

In the event that we determine to register any of our securities under the Securities Act (subject to certain exceptions), either for our own account or for the account of other security holders, the holders of the holders of the registrable securities are entitled to certain “piggyback” registration rights allowing the holders to include their shares in such registration, subject to certain marketing and other limitations. As a result, whenever we propose to file a registration statement under the Securities Act, other than with respect to certain registrations, including related to the sale of securities to employees pursuant to employee benefit plans, the offer and sale of debt securities, or a Securities and Exchange Commission Rule 145 transaction, the holders of the registrable securities are entitled to notice of the registration and have the right, subject to limitations that the underwriters may impose on the number of shares included in the registration, to include their shares in the registration. In an underwritten offering, the underwriters have the right, subject to specified conditions, to limit the number of shares such holders may include.

We will pay the registration expenses, excluding certain expenses related to the sale of shares, of the holders of the shares registered pursuant to the Form S-1 demand, Form S-3 demand and piggyback registration rights described above, including the reasonable expenses of one counsel for the selling holders not to exceed $25,000.

The Form S-1 demand, Form S-3 demand and piggyback registration rights described above will terminate, with respect to any particular stockholder, upon the earlier of (i) February 18, 2025, (ii) the date that Rule 144 or another similar exemption under the Securities Act is available to such stockholder for the sale of all of such stockholder’s shares without limitation during a three-month period, or (iii) upon the consummation of a merger, consolidation or the sale of substantially all of our assets.

Some provisions of Delaware law, our amended and restated certificate of incorporation and our amended and restated bylaws contain provisions that could make the following transactions more difficult: acquisition of us by means of a tender offer; acquisition of us by means of a proxy contest or otherwise; or removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders may otherwise consider to be in their best interest or in our best interests, including transactions that might result in a premium over the market price for our shares.

These provisions, summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

We are subject to Section 203 of the Delaware General Corporation Law, which prohibits persons deemed “interested stockholders” from engaging in a “business combination” with a publicly-held Delaware corporation for three years following the date these persons become interested stockholders unless the business combination is, or the transaction in which the person became an interested stockholder was, approved in a prescribed manner or another prescribed exception applies. Generally, an “interested stockholder” is a person who, together with affiliates and associates, beneficially owns, or within three years prior to the determination of interested stockholder status did own, 15% or more of a corporation’s voting stock. Generally, a “business combination” includes a merger, asset or stock sale, or other transaction resulting in a financial benefit to the interested stockholder. The existence of this provision may have an anti-takeover effect with respect to transactions not approved in advance by the board of directors, such as discouraging takeover attempts that might result in a premium over the market price of our common stock.

The ability to issue undesignated preferred stock makes it possible for our board of directors to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to change control of us. These and other provisions may have the effect of deterring hostile takeovers or delaying changes in control or management of our company.

Our amended and restated certificate of incorporation and our amended and restated bylaws provide that a special meeting of stockholders may be called only by our board of directors, or by our President or Chief Executive Officer.

Our amended and restated bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of the board of directors or a committee of the board of directors.

Our amended and restated certificate of incorporation and our amended and restated bylaws eliminate the right of stockholders to act by written consent without a meeting.

Our board of directors is divided into three classes. The directors in each class serve for a three-year term, one class being elected each year by our stockholders, with staggered three-year terms. Only one class of directors is elected at each annual meeting of our stockholders, with the other classes continuing for the remainder of their respective three-year terms. Because our stockholders do not have cumulative voting rights, our stockholders holding a majority of the shares of common stock outstanding are able to elect all of our directors. Our amended and restated certificate of incorporation provides for the removal of any of our directors only for cause and requires a stockholder vote by the holders of at least a 66-2/3% of the voting power of the then outstanding voting stock.

Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of the board, may only be filled by a resolution of the board of directors unless the board of directors determines that such vacancies shall be filled by the stockholders. This system of electing and removing directors and filling vacancies may tend to discourage a third party from making a tender offer or otherwise attempting to obtain control of us, because it generally makes it more difficult for stockholders to replace a majority of the directors.

Our amended and restated certificate of incorporation and amended and restated bylaws provide that the Court of Chancery of the State of Delaware is the sole and exclusive forum for (i) any state law derivative action or proceeding brought on our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors or officers to us or our stockholders, (iii) any action asserting a claim against us arising pursuant to any provision of the Delaware General Corporation Law or our amended and restated certificate of incorporation or amended and restated bylaws or (iv) any action asserting a claim against us governed by the internal affairs doctrine; provided that, the exclusive forum provision will not apply to suits brought to enforce any liability or duty created by the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction; and provided further that, if and only if the Court of Chancery of the State of Delaware dismisses any such action for lack of subject matter jurisdiction, such action may be brought in another state or federal court sitting in the State of Delaware. Our amended and restated bylaws also provide that the federal district courts of the United States of America will be the exclusive forum for the resolution of any complaint asserting a cause or causes of action under the Securities Act. Such provision is intended to benefit and may be enforced by us, our officers and directors, the underwriters to any offering giving rise to such complaint and any other professional or entity whose profession gives authority to a statement made by that person or entity and who has prepared or certified any part of the documents underlying the offering. Nothing in our amended and restated certificate of incorporation or amended and restated bylaws precludes stockholders that assert claims under the Exchange Act from bringing such claims in state or federal court, subject to applicable law.

This choice of forum provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or any of our directors, officers, other employees or stockholders, which may discourage lawsuits with respect to such claims, although our stockholders will not be deemed to have waived our compliance with federal securities laws and the rules and regulations thereunder.

The amendment of any of the above provisions, except for the provision making it possible for our board of directors to issue undesignated preferred stock, would require approval by a stockholder vote by the holders of at least a 66-2/3% of the voting power of the then outstanding voting stock.

The provisions of the Delaware General Corporation Law, our amended and restated certificate of incorporation and our amended and restated bylaws could have the effect of discouraging others from attempting hostile takeovers and, as a consequence, they may also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. These provisions may also have the effect of preventing changes in our management. It is possible that these provisions could make it more difficult to accomplish transactions that stockholders may otherwise deem to be in their best interests.

Our common stock and public warrants are listed on the Nasdaq Global Select Market under the symbols “RVMD” and “RVMDW,” respectively.

The transfer agent and registrar for our common stock and warrants is Equiniti Trust Company, LLC. The transfer agent and registrar’s address is 6201 15th Avenue, Brooklyn, New York 11219.