=== SEC Form 4 — Statement of Changes in Beneficial Ownership ===
Document Type: 4
Period of Report: 2026-03-03
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: 2026-03-03 | Code: M (Exercise of derivative)
Shares: +23 | Price: $0.00
Shares Owned After: 133,804 | 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: 2026-03-03 | Code: F (Payment of exercise/tax)
Shares: -2,798 | Price: $250.61
Total Value: $701,206.78
Shares Owned After: 131,006 | 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: 2026-03-04 | Code: S (Open market sale)
Shares: -777 | Price: $257.91
Total Value: $200,396.07
Shares Owned After: 130,229 | 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 #4]
Security: Common Stock
Date: 2026-03-04 | Code: S (Open market sale)
Shares: -8,547 | Price: $269.22
Total Value: $2,300,985.73
Shares Owned After: 121,682 | Ownership: D (Direct)
Footnotes:
[F4] Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $269.17 to a high of $269.2201. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
--- Derivative Transactions ---
[Transaction #1]
Security: Dividend Equivalent Rights
Date: 2026-03-03 | Code: M (Exercise of derivative)
Shares: -23.8133 | Price: $0.00
Shares Owned After: 304.413 | 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.
F4: Represents the weighted average sale price per share. These shares were sold in multiple transactions at prices ranging from a low of $269.17 to a high of $269.2201. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price.
--- Signature ---
/s/ By: /s/ Sandra Garcia Attorney-in-Fact For: Cynthia Tregillis (2026-03-05)
