Exhibit 4.2

DESCRIPTION OF THE REGISTRANT’S SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

As of December 31, 2025, ACV Auctions Inc. had one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended, or the Exchange Act: our common stock, $0.001 par value per share. References herein to the terms “ we,” “our” and “ us” refer to ACV Auctions Inc. and its subsidiaries.

The following description of our capital stock is a summary and does not purport to be complete. It is subject to, and qualified in its entirety by reference to, the applicable provisions of our amended and restated certificate of incorporation, our amended and restated bylaws and our investor rights agreement, most recently amended in September 2020, each of which are filed as exhibits to our Annual Report on Form 10-K, of which this Exhibit 4.2 is a part, and are incorporated by reference herein. We encourage you to read our amended and restated certificate of incorporation, our amended and restated bylaws, our amended and restated investor rights agreement and the applicable provisions of the Delaware General Corporation Law for more information.

General

Our amended and restated certificate of incorporation provides for a single-class of common stock(the “Common stock”). In addition, our amended and restated certificate of incorporation authorizes shares of undesignated preferred stock, the rights, preferences and privileges of which may be designated from time to time by our board of directors and filed in accordance with Delaware law.

Our authorized capital stock consists of 2,020,000,000 shares, all with a par value of $0.001 per share, of which 2,000,000,000 shares are designated Common stock and 20,000,000 shares are designated preferred stock.

Our board of directors is authorized, without stockholder approval except as required by the listing standards of Nasdaq, to issue additional shares of our capital stock.

Common Stock

Voting Rights

The Common stock is entitled to one vote per share on any matter that is submitted to a vote of our stockholders. Our amended and restated certificate of incorporation does not provide for cumulative voting for the election of directors.

Economic Rights

Except as otherwise expressly provided in our amended and restated certificate of incorporation or required by applicable law, all shares of Common stock have the same rights, privileges and powers and rank equally, share ratably and be identical in all respects for all matters, including those described below.

Dividends and Distributions

Subject to preferences that may apply to any shares of convertible preferred stock outstanding at the time, the holders of Common stock are entitled to share equally, identically and ratably, on a per share basis, with respect to any dividend or distribution of cash or property paid or distributed by the company, unless different treatment of the shares of the affected class is approved by the affirmative vote of the holders of a majority of the outstanding shares of such affected class, voting separately as a class.

Liquidation Rights

On our liquidation, dissolution or winding-up, the holders of Common stock will be entitled to share equally, identically and ratably in all assets remaining after the payment of any liabilities, liquidation preferences and accrued or declared but unpaid dividends, if any, with respect to any outstanding convertible preferred stock, unless a different treatment is approved by the affirmative vote of the holders of a majority of the outstanding shares of such affected class, voting separately as a class.

    

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No Preemptive or Similar Rights

Our Common stock is not entitled to preemptive rights, and is not subject to conversion, redemption or sinking fund provisions.

Registration Rights

We are party to an investors’ rights agreement that provides that certain holders of our capital stock have certain registration rights, as set forth below. The registration of shares of our common stock by the exercise of registration rights described below would enable the holders to sell these shares without restriction under the Securities Act of 1933, as amended, or the Securities Act, when the applicable registration statement is declared effective. We will pay the registration expenses, other than underwriting discounts and commissions, of the shares registered by the demand, piggyback and Form S-3 registrations described below.

Generally, in an underwritten offering, the managing underwriter, if any, has the right, subject to specified conditions, to limit the number of shares such holders may include. The demand, piggyback and Form S-3 registration rights under our investors rights agreement will expire upon the earliest to occur of: (1) the closing of a “Deemed Liquidation Event”, as defined in our amended and restated certificate of incorporation in effect immediately prior to the completion of our initial public offering; or (2) with respect to any particular stockholder, such time as such stockholder can sell all of its shares under Rule 144 of the Securities Act or another similar exemption during any three-month period.

Anti-Takeover Provisions

Certificate of Incorporation and Bylaws

Because our stockholders do not have cumulative voting rights, stockholders holding a majority of the voting power of our shares of common stock will be able to elect all of our directors. Our amended and restated certificate of incorporation and amended and restated bylaws provide for stockholder actions at a duly called meeting of stockholders. A special meeting of stockholders may be called by a majority of our board of directors, the chair of our board of directors, our chief executive officer or our lead independent director. Our amended and restated bylaws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to our board of directors.

Our amended and restated certificate of incorporation provides for a single-class common stock structure, under which each share of our Common stock is entitled to one vote per share. As a result, all matters requiring stockholder approval—including the election of directors and significant corporate transactions such as a merger or sale of the company—are determined by a proportionate vote of all stockholders, and no single group of stockholders holds disparate voting control through the ownership of high-vote stock.

In accordance with our amended and restated certificate of incorporation, our board of directors is divided into three classes with staggered three-year terms.

The foregoing provisions will make it more difficult for another party to obtain control of us by replacing our board of directors. Since our board of directors has the power to retain and discharge our officers , these provisions could also make it more difficult for existing stockholders or another party to effect a change in management. In addition, the authorization of 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 our control.

The provisions of our certificate of incorporation and bylaws are intended to promote management stability and facilitate our ability to pursue long-term strategic initiatives. These provisions are designed to reduce our vulnerability to unsolicited takeover proposals and to discourage certain tactics that may be used in proxy fights. However, these provisions could have the effect of delaying or preventing a change in control, discouraging others from making tender offers for our shares, or preventing stockholders from receiving a premium for their shares in a transaction that is not approved by our board of directors.

    

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Section 203 of the Delaware General Corporation Law

We are subject to Section 203 of the Delaware General Corporation Law, which prohibits a Delaware corporation from engaging in any business combination with any interested stockholder for a period of three years after the date that such stockholder became an interested stockholder, subject to certain exceptions.

Choice of Forum

Our amended and restated certificate of incorporation provides that the Court of Chancery of the State of Delaware (or, if and only if the Court of Chancery of the State of Delaware lacks subject matter jurisdiction, any state court located within the State of Delaware or, if and only if all such state courts lack subject matter jurisdiction, the federal district court for the District of Delaware) is the sole and exclusive forum for the following claims or causes of action under Delaware statutory or common law: (1) any derivative claim or cause of action brought on our behalf; (2) any claim or cause of action asserting a claim of breach of a fiduciary duty owed by any of our current or former directors , officers, or other employees to us or our stockholders; (3) any claim or cause of action against us or any of our current or former directors , officers or other employees arising out of or pursuant to any provision of the Delaware General Corporation Law, our amended and restated certificate of incorporation or our amended and restated bylaws; (4) any claim or cause of action arising under or seeking to interpret, apply, enforce or determine the validity of our amended and restated certificate of incorporation or our amended and restated bylaws (including any right, obligation, or remedy thereunder); and (5) any claim or cause of action as to which the Delaware General Corporation Law confers jurisdiction on the Court of Chancery of the State of Delaware; and (6) any claim or cause of action against us or any of our current or former directors, officers, or other employees that is governed by the internal-affairs doctrine, in all cases to the fullest extent permitted by law and subject to the court having personal jurisdiction over the indispensable parties named as defendants. This choice of forum provision would not apply to suits brought to enforce a duty or liability created by the Securities Act, the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction, or the Securities Act.

Our amended and restated certificate of incorporation further provides that, unless we consent in writing to the selection of an alternative forum, to the fullest extent permitted by law, the federal district courts of the United States will be the exclusive forum for resolving any complaint asserting a cause or causes of action arising under the Securities Act, including all causes of action asserted against any defendant to such complaint. For the avoidance of doubt, this 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 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.

While the Delaware courts have determined that such choice of forum provisions are facially valid, there is no assurance that a court in another jurisdiction would enforce the choice of forum provision contained in the amended and restated certificate of incorporation. If a court were to find such provision to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, which could harm our business, results of operations and financial condition. Additionally, our amended and restated certificate of incorporation provides that any person or entity holding, owning or otherwise acquiring any interest in any of our securities shall be deemed to have notice of and consented to these provisions. Investors also cannot waive compliance with the federal securities laws and the rules and regulations thereunder.

Exchange Listing

Our Common stock is listed on The New York Stock Exchange under the symbol “ACVA.”

Transfer Agent and Registrar

The transfer agent and registrar for our Common stock is Computershare Trust Company,

N.A. The transfer agent’s address is 250 Royall Street, Canton, Massachusetts 02021.