UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a)

of the Securities Exchange Act of 1934 (Amendment No.)

Filed by the Registrant ☒

Filed by a party other than the Registrant ☐

Check the appropriate box:

Quantum Corporation

(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

QUANTUM CORPORATION Important Notice Regarding the Availability of Proxy Materials forthe Shareholder Meeting To Be Held on August 15, 2024 This communication is not a form for voting and presents only an overview of the more complete proxy materials that are available to you on the Internet or by mail. We encourage you to access and review all of the important information contained in the proxy materials before voting. This Notice, the Proxy Statement, and the Annual Report on Form 10-K are available at www.viewproxy.com/QMCO/2024. If you want to receive a paper or e-mail copy of these documents, you must request one. There is no charge to you for requesting a copy. Please make your request for a copy as instructed below on or before August 7, 2024 to facilitate timely delivery. Important information regarding the Internet availability of the Company’s proxy materials, instructions for accessing your proxy materials and voting online and instructions for requesting paper or e-mail copies of your proxy materials are provided on the reverse side of this Notice. To the Shareholders of QUANTUM CORPORATION: Notice is hereby given that the Annual Meeting of Shareholders of Quantum Corporation will be held virtually on August 15, 2024 at 8:30 a.m., Pacific Time to consider and vote on the following matters: 1. Election of seven directors to serve for a term expiring at the 2025 annual meeting of shareholders or until their successors are duly qualified and elected. (1) James J. Lerner (2) Todd W. Arden (3) Donald J. Jaworski (4) Hugues Meyrath (5) Christopher D. Neumeyer (6) John R. Tracy (7) Yue Zhou (Emily) White 2. Approval of an amendment to the Amended and Restated Certificate of Incorporation to effect a reverse stock split of the issued shares of our common stock at a ratio ranging from 1 share-for-5 shares up to a ratio of 1 share-for-20 shares, with the exact ratio to be selected by the Board of Directors and set forth in a public announcement. 3. Approval of an amendment to the Quantum Corporation 2023 Long-Term Incentive Plan to increase the number of shares of common stock reserved for issuance thereunder by 5,000,000 shares. 4. Approval of the compensation of our named executive officers, on a non-binding advisory basis. 5. Ratification of the appointment of Grant Thornton LLP as our independent registered public accounting firm for the year ending March 31, 2025. The Board of Directors recommends that you vote FOR each nominee in Proposal 1 and FOR Proposals 2, 3, 4 and 5. The Securities and Exchange Commission rules permit us to make our proxy materials available to our shareholders via the Internet. Material for the Annual Meeting may be requested by one of the following methods: To view your proxy materials online, go to www.viewproxy.com/QMCO/2024. Have the 11-digit control number (located below) available when you access the website and follow the instructions. Call 1-877-777-2857 TOLL FREE By e-mail at: requests@viewproxy.com * If requesting material by e-mail, please send a blank e-mail with the company name and your 11-digit control number (located below) in the subject line. No other requests, instructions, or other inquiries should be included with your e-mail requesting material. You must use the 11-digit control number located in the box below. Proxies transmitted by Internet or Telephone must be submitted prior to 11:59 p.m., Eastern Time, on August 14, 2024. CONTROL NUMBER QUANTUM CORPORATION HOW TO REGISTER FOR THE VIRTUAL ANNUAL MEETING The 2024 Annual Meeting of Shareholders of Quantum Corporation will be held virtually on August 15, 2024 at 8:30 a.m., Pacific Time. As a registered holder as of the close of business on June 20, 2024, the record date for the Annual Meeting, you may attend the Annual Meeting by first registering at www.viewproxy.com/QMCO/2024 using your control number (listed on the bottom of the first page). Your registration must be received by 11:59 p.m., Eastern Time, on August 14, 2024. On the day of the meeting, you may log in to the meeting using the invitation provided upon registration and follow the instructions to vote your shares. Please have your control number with you during the meeting in order to vote. Further instructions on how to attend and vote at the Annual Meeting are contained in the Proxy Statement and at www.viewproxy.com/QMCO/2024. PROXY MATERIALS AVAILABLE TO VIEW OR RECEIVE The following proxy materials are available to you to review: • Annual Report on Form 10-K • Proxy Statement • Notice HOW TO ACCESS YOUR PROXY MATERIALS View Online: Have your 11-digit control number in hand and visit www.viewproxy.com/QMCO/2024. Request and Receive a Paper or E-Mail Copy: By Internet: www.viewproxy.com/QMCO/2024 By Telephone: 1-877-777-2857 TOLL FREE By E-Mail: requests@viewproxy.com. Please include the company name and your 11-digit control number in the subject line; do not include any other text or message in the e-mail. VOTING METHODS Via Internet Prior to the Annual Meeting: Go to www.AALVote.com/QMCO. Have your 11-digit control number available and follow the prompts. Your electronic vote prior to the Annual Meeting authorizes the named proxies to vote your shares in the same manner as if you marked, signed, dated, and returned a proxy card. Via Internet During the Annual Meeting: Go to www.AALvote.com/QMCO. Have your 11-digit control number available and follow the prompts. Via Mail Prior to the Annual Meeting: Request a paper copy of the materials which includes a proxy card. Follow the instructions on the proxy card for voting by mail. Via Telephone Prior to the Annual Meeting: Request a paper copy of the materials, which includes a proxy card. Follow the instructions on the proxy card for voting by telephone.