Western Digital (WDC)

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-02-20 10b5-1 Pre-arranged Plan: Yes --- Issuer --- Name: WESTERN DIGITAL CORP (WDC) CIK: 0000106040 --- Reporting Owner --- Name: Tregillis Cynthia L CIK: 0002057088 Role: Officer (Chief Legal Officer & Corp Sec) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-02-20 | Code: M (Exercise of derivative) Shares: +3 | Price: $0.00 Shares Owned After: 136,541 | Ownership: D (Direct) Footnotes: [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. [Transaction #2] Security: Common Stock Date: 2026-02-20 | Code: F (Payment of exercise/tax) Shares: -244 | Price: $285.52 Total Value: $69,666.88 Shares Owned After: 136,297 | Ownership: D (Direct) Footnotes: [F2] Payment of tax obligation by withholding securities incident to the vesting of securities in accordance with Rule 16b-3(e). [Transaction #3] Security: Common Stock Date: 2026-02-21 | Code: M (Exercise of derivative) Shares: +9 | Price: $0.00 Shares Owned After: 136,306 | Ownership: D (Direct) Footnotes: [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. [Transaction #4] Security: Common Stock Date: 2026-02-21 | Code: F (Payment of exercise/tax) Shares: -1,109 | Price: $285.52 Total Value: $316,641.68 Shares Owned After: 135,197 | Ownership: D (Direct) Footnotes: [F2] Payment of tax obligation by withholding securities incident to the vesting of securities in accordance with Rule 16b-3(e). [Transaction #5] Security: Common Stock Date: 2026-02-23 | Code: S (Open market sale) Shares: -130 | Price: $283.83 Total Value: $36,897.90 Shares Owned After: 135,067 | Ownership: D (Direct) Footnotes: [F3] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 23, 2025. [Transaction #6] Security: Common Stock Date: 2026-02-24 | Code: S (Open market sale) Shares: -308 | Price: $281.70 Total Value: $86,763.60 Shares Owned After: 134,759 | Ownership: D (Direct) Footnotes: [F3] The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 23, 2025. --- Derivative Transactions --- [Transaction #1] Security: Dividend Equivalent Rights Date: 2026-02-20 | Code: M (Exercise of derivative) Shares: -3.234 | Price: $0.00 Shares Owned After: 344.2281 | Ownership: D (Direct) Footnotes: [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. [Transaction #2] Security: Dividend Equivalent Rights Date: 2026-02-21 | Code: M (Exercise of derivative) Shares: -9.4399 | Price: $0.00 Shares Owned After: 334.7882 | Ownership: D (Direct) Footnotes: [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. [F1] The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. --- Footnotes (Complete Index) --- F1: The dividend equivalent rights were converted into, and paid in the form of, shares of the Issuer's common stock on a one-for-one basis in connection with the vesting of restricted stock units to which the dividend equivalent rights relate. A cash amount was also paid to the holder to settle a fractional dividend equivalent right. F2: Payment of tax obligation by withholding securities incident to the vesting of securities in accordance with Rule 16b-3(e). F3: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 23, 2025. --- Signature --- /s/ By: /s/ Sandra Garcia Attorney-in-Fact For: Cynthia Tregillis (2026-02-24)