QUANTUM CORP /DE/ (QMCO) · Insider Trading (Form 4) SEC Filing

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-08-03 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: QUANTUM CORP /DE/ (QMCO) CIK: 0000709283 --- Reporting Owner --- Name: Craythorne Anthony CIK: 0002075430 Role: Officer (Chief Revenue Officer) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-08-03 | Code: S (Open market sale) Shares: -1,478 | Price: $10.73 Total Value: $15,856.13 Shares Owned After: 13,522 | Ownership: D (Direct) Footnotes: [F1] Represents the number of shares automatically sold on a non-discretionary basis, to cover tax withholding obligations in connection with the vesting of restricted stock units granted on January 1, 2026. This Form 4 is a required filing under the Securities Exchange Act of 1934, and the securities in this Form 4 are subject to the terms of that certain Lock-Up Letter Agreement, by and between the issuer and the Reporting Person, dated as of June 1, 2026, and is subject to clause (h) thereunder. [F2] The shares were sold on August 3, 2026 at a price of $10.7281 per share. --- Footnotes (Complete Index) --- F1: Represents the number of shares automatically sold on a non-discretionary basis, to cover tax withholding obligations in connection with the vesting of restricted stock units granted on January 1, 2026. This Form 4 is a required filing under the Securities Exchange Act of 1934, and the securities in this Form 4 are subject to the terms of that certain Lock-Up Letter Agreement, by and between the issuer and the Reporting Person, dated as of June 1, 2026, and is subject to clause (h) thereunder. F2: The shares were sold on August 3, 2026 at a price of $10.7281 per share. --- Signature --- /s/ Tara Ilges, attorney-in-fact for Anthony Craythorne (2026-08-05)