[Form 4] Western Digital Corp. Insider Trading Activity

Rhea-AI Filing Summary

Gene M. Zamiska, Senior Vice President, Global Accounting & Chief at Western Digital Corporation (WDC), reported multiple transactions in the issuer's common stock associated with the vesting of restricted stock units and planned sales under a Rule 10b5-1 trading plan. Dividend equivalent rights tied to RSUs converted into 6.1142 shares and were paid in common stock on a one-for-one basis, with a fractional cash settlement. Withholding to satisfy taxes resulted in 1,797 shares disposed at a price of $74.66 per share. Separate open-market sales under a 10b5-1 plan disposed of 3,160 shares at $75.68 and 1,828 shares at $74.78, reducing beneficial ownership to 29,732 shares after the reported trades.

The transactions include both non-derivative share acquisitions from RSU settlement and routine dispositions pursuant to a pre-established trading plan, showing a net decline in direct holdings following tax withholding and planned sales.

Positive

• Use of a Rule 10b5-1 trading plan provides pre-established execution and reduces insider-timing concerns
• Dividend equivalent conversion into shares indicates equity compensation being vested and settled in stock rather than cash

Negative

• Net reduction in direct beneficial ownership from 36,517 shares to 29,732 shares following tax withholding and planned sales
• Material sales executed (total disposed: 6,785 shares) represent a meaningful portion of the previously reported holding for this individual

Insights

Securities Analyst

TL;DR: Insider realized shares from RSU vesting and executed pre-planned sales, modestly reducing direct beneficial ownership.

The filing discloses standard insider activity: conversion of dividend equivalent rights into a small number of shares and tax-withholding disposals, combined with additional sales executed under a Rule 10b5-1 plan. The sales prices reported (around $74.66–$75.68) reflect the execution prices for the disposed lots. This pattern is typical of executives monetizing vested equity and meeting tax obligations while using an established trading plan to avoid ad hoc timing concerns.

Corporate Governance Expert

TL;DR: Disclosure aligns with governance best practices: use of 10b5-1 plan and tax-withholding noted; activity appears routine.

The report clearly states the use of a Rule 10b5-1 trading plan adopted on March 6, 2025, and the mechanics of RSU settlement and dividend-equivalent conversion. The filing includes an attorney-in-fact signature, indicating proper execution of Form 4. No unusual derivative activity or indirect ownership changes are disclosed beyond routine direct share movements tied to vesting and planned sales.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a 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). See Instruction 10.

1. Name and Address of Reporting Person^*

Zamiska Gene M.

(Last) (First) (Middle)

C/O WESTERN DIGITAL CORPORATION

5601 GREAT OAKS PARKWAY

(Street)

SAN JOSE CA 95119

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
WESTERN DIGITAL CORP [ WDC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP, Global Accounting & Chief

3. Date of Earliest Transaction (Month/Day/Year)
08/21/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/21/2025		M		6(1)	A	$0.0	36,517	D
Common Stock	08/21/2025		F		1,797(2)	D	$74.66	34,720	D
Common Stock	08/21/2025		S(3)		3,160	D	$75.68	31,560	D
Common Stock	08/22/2025		S(3)		1,828	D	$74.78	29,732	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Dividend Equivalent Rights	(1)	08/21/2025		M			6.1142	(1)	(1)	Common Stock	6.1142	$0.0	50.2625	D

Explanation of Responses:

1. 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.

2. Payment of tax obligation by withholding securities incident to the vesting of securities in accordance with Rule 16b-3(e).

3. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 6, 2025.

	By: /s/ Sandra Garcia Attorney-in-Fact For: Gene Zamiska	08/25/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What transactions did Gene M. Zamiska report on Form 4 for WDC?

The report shows conversion of 6.1142 dividend-equivalent shares, tax-withholding disposal of 1,797 shares at $74.66, and Rule 10b5-1 plan sales of 3,160 shares at $75.68 and 1,828 shares at $74.78.

How many WDC shares does the reporting person own after these transactions?

Following the reported transactions, the filing shows 29,732 shares beneficially owned directly.

Was a trading plan used for the sales reported in the Form 4?

Yes. The filing states the sales were effected pursuant to a Rule 10b5-1 trading plan adopted on March 6, 2025.

Did the filing include any derivative transactions for WDC?

Yes. It reports dividend equivalent rights converted into common stock related to RSU vesting; no other derivative exercises or new options were reported.

Were any shares sold to satisfy tax withholding?

Yes. The filing discloses 1,797 shares were disposed to pay tax obligations incident to vesting, per Rule 16b-3(e).