X0508 4 2025-11-19 0 0000106040 WESTERN DIGITAL CORP WDC 0001021762 STREETER STEPHANIE A C/O WESTERN DIGITAL CORPORATION 5601 GREAT OAKS PARKWAY SAN JOSE CA 95119 1 0 0 0 0 Common Stock 2025-11-20 4 A 0 1585 0.0 A 1585 D Common Stock 2025-11-19 4 M 0 16 0.0 A 40407 I By Family Trust Dividend Equivalent Rights 2025-11-19 4 M 0 16.8276 0.0 D Common Stock 16.8276 0 D Represents the grant of restricted stock units to the Reporting Person. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. 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. Includes change in form of beneficial ownership of shares of Issuer's common stock in connection with the Reporting Person's contribution of shares owned outright to the Reporting Person's Family Trust Account and the vesting of the Reporting Person's restricted stock unit award. With respect to the vested restricted stock unit award, the underlying shares were issued directly to the Reporting Person's Family Trust account. Additionally includes 1,984 additional stock units acquired by the Reporting Person in connection with the Issuer's spin-off (the "Spin-Off") of a then-wholly owned subsidiary of the Issuer on February 21, 2025. Pursuant to an Employee Matters Agreement, at the effective time of the Spin-Off, each outstanding Issuer stock unit was adjusted and converted into additional stock units based on the equity conversion ratio of 1.452526 per every Issuer stock unit. By: /s/ Sandra Garcia Attorney-in-Fact For: Stephanie A. Streeter 2025-11-21