United States securities and exchange commission logo March 11, 2021 George Chamoun Chief Executive Officer ACV Auctions Inc. 640 Ellicott Street, #321 Buffalo, New York 14203 Re: ACV Auctions Inc. Registration Statement on Form S-1 Filed February 26, 2021 File No. 333-253617 Dear Mr. Chamoun: We have reviewed your registration statement and have the following comments. In some of our comments, we may ask you to provide us with information so we may better understand your disclosure. Please respond to this letter by amending your registration statement and providing the requested information. If you do not believe our comments apply to your facts and circumstances or do not believe an amendment is appropriate, please tell us why in your response. After reviewing any amendment to your registration statement and the information you provide in response to these comments, we may have additional comments. Registration Statement on Form S-1 filed February 26, 2021 Management's Discussion and Analysis of Financial Condition and Results of Operations Impact of COVID-19 on Our Business Adjusted EBITDA, page 65 1. We note your disclosure of Adjusted EBITDA on a quarterly basis. In accordance with Item 10(e) of Regulation S-K, please reconcile your quarterly non-GAAP financial measures to the most directly comparable GAAP measure. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. George Chamoun ACV Auctions Inc. March 11, 2021 Page 2 Refer to Rules 460 and 461 regarding requests for acceleration. Please allow adequate time for us to review any amendment prior to the requested effective date of the registration statement. You may contact Scott Stringer at 202-551-3272 or Angela Lumley at 202-551-3398 if you have questions regarding comments on the financial statements and related matters. Please contact Scott Anderegg at 202-551-3342 or Dietrich King at 202-551-8071 with any other questions. Sincerely, FirstName LastNameGeorge Chamoun Division of Corporation Finance Comapany NameACV Auctions Inc. Office of Trade & Services March 11, 2021 Page 2 cc: Alan Hambelton FirstName LastName