Quantum (QMCO)

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-04-01 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: QUANTUM CORP /DE/ (QMCO) CIK: 0000709283 --- Reporting Owner --- Name: Nash Laura A. CIK: 0001979364 Role: Officer (Chief Accounting Officer) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-04-02 | Code: S (Open market sale) Shares: -109 | Price: $5.44 Total Value: $592.96 Shares Owned After: 11,030 | 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 April 1, 2024. [F2] Represents a weighted average price. These shares were sold as part of block trades for multiple security holders of the issuer on April 2, 2026, at a price ranging from $5.43 to $5.45. The Reporting Person undertakes to provide upon request by the Securities and Exchange Commission, the issuer, or a securityholder of the issuer detailed information regarding the number of shares sold and the prices at which the transactions were executed. --- Derivative Transactions --- [Transaction #1] Security: Employee Stock Option (right to buy) Date: 2026-04-01 | Code: A (Grant or award) Shares: +49,500 | Price: $0.00 Exercisable: N/A | Expires: 2033-04-01 Shares Owned After: 49,500 | Ownership: D (Direct) Footnotes: [F3] This nonstatutory stock option vests over four years in equal monthly installments beginning on April 1, 2026, subject to the Reporting Persons continued service through each vesting date. [F3] This nonstatutory stock option vests over four years in equal monthly installments beginning on April 1, 2026, subject to the Reporting Persons continued service through each vesting date. --- 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 April 1, 2024. F2: Represents a weighted average price. These shares were sold as part of block trades for multiple security holders of the issuer on April 2, 2026, at a price ranging from $5.43 to $5.45. The Reporting Person undertakes to provide upon request by the Securities and Exchange Commission, the issuer, or a securityholder of the issuer detailed information regarding the number of shares sold and the prices at which the transactions were executed. F3: This nonstatutory stock option vests over four years in equal monthly installments beginning on April 1, 2026, subject to the Reporting Persons continued service through each vesting date. --- Signature --- /s/ /s/ Tara Ilges, Attorney-in-Fact for Laura A. Nash (2026-04-03)