MATTHEW E. MASSENGILL - 20 Nov 2025 Form 4 Insider Report for WESTERN DIGITAL CORP (WDC)

Role: Director
Signature: By: /s/ Sandra Garcia Attorney-in-Fact For: Matthew E. Massengill
Issuer symbol: WDC
Transactions as of: 20 Nov 2025
Net transactions value: $0
Form type: 4
Filing time: 21 Nov 2025, 17:31:55 UTC
Previous filing: 22 Sep 2025
Next filing: 22 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
MASSENGILL MATTHEW E	Director	C/O WESTERN DIGITAL CORPORATION, 5601 GREAT OAKS PARKWAY, SAN JOSE	By: /s/ Sandra Garcia Attorney-in-Fact For: Matthew E. Massengill	21 Nov 2025	0001232826

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	WDC	Common Stock	Award	$0	+1,585	+5.8%	$0.000000	28,897	20 Nov 2025	Direct	F1, F2
holding	WDC	Common Stock						36,926	20 Nov 2025	By Family Trust
holding	WDC	Common Stock						500	20 Nov 2025	by IRA

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	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.
F2	Includes 8,508 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.

Content

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.

Includes 8,508 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.