Cynthia L. Tregillis - 20 Jan 2026 Form 4 Insider Report for WESTERN DIGITAL CORP (WDC)

Role
Chief Legal Officer & Corp Sec
Signature
By: /s/ Sandra Garcia Attorney-in-Fact For: Cynthia Tregillis
Issuer symbol
WDC
Transactions as of
20 Jan 2026
Net transactions value
-$290,104
Form type
4
Filing time
21 Jan 2026, 17:14:28 UTC
Previous filing
22 Dec 2025
Next filing
06 Feb 2026
SEC
View on sec.gov

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Tregillis Cynthia L Chief Legal Officer & Corp Sec C/O WESTERN DIGITAL CORPORATION, 5601 GREAT OAKS PARKWAY, SAN JOSE By: /s/ Sandra Garcia Attorney-in-Fact For: Cynthia Tregillis 21 Jan 2026 0002057088

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction WDC Common Stock Options Exercise $0 +11 +0.01% $0.000000 144,607 20 Jan 2026 Direct F1
transaction WDC Common Stock Tax liability $187,741 -842 -0.58% $222.97 143,765 20 Jan 2026 Direct F2
transaction WDC Common Stock Sale $102,363 -447 -0.31% $229.00 143,318 21 Jan 2026 Direct F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction WDC Dividend Equivalent Rights Options Exercise $0 -11 -3.1% $0.000000 347 20 Jan 2026 Common Stock 11 Direct F1
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
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.