[Form 4] Western Digital Corp. Insider Trading Activity

Rhea-AI Filing Summary

Gene M. Zamiska, Senior Vice President & Principal Accounting Officer of Western Digital Corporation (WDC), reported multiple transactions in the issuer's common stock on August 25-26, 2025. On 08/25/2025 dividend equivalent rights were converted into 2.7201 shares upon RSU vesting and paid in kind, increasing his holding to 29,734 shares. Also on 08/25/2025 798 shares were withheld to satisfy taxes at an average implied price of $79.22, leaving 28,936 shares. On 08/26/2025 he sold 814 shares under a Rule 10b5-1 plan at an average price of $79.10, leaving 28,122 shares.

The Form 4 was signed by an attorney-in-fact on 08/27/2025. Explanations note conversion of dividend equivalents, tax-withholding for vesting, and that the sale was pursuant to a March 6, 2025 Rule 10b5-1 trading plan.

Positive

• Conversion of dividend equivalents into shares on 08/25/2025 reflects standard RSU vesting and increases beneficial ownership by 2.7201 shares.
• Sale executed under a Rule 10b5-1 plan adopted March 6, 2025, indicating pre-planned trading and an affirmative defense to insider-trading claims.
• Tax obligation satisfied by withholding (798 shares) in accordance with Rule 16b-3(e), showing routine compensation tax handling.

Negative

• Officer sold 814 shares on 08/26/2025 at ~$79.10 per share, reducing holdings to 28,122 shares—represents an actual disposition of stock.

Insights

Securities Analyst

TL;DR: Officer received small equity from RSU vesting, paid taxes via share withholding, and sold a modest position under a pre-established 10b5-1 plan.

The transactions are routine compensation and tax-related actions rather than opportunistic executive sales. The conversion of dividend equivalent rights into 2.7201 shares reflects RSU vesting treatment; the withholding of 798 shares to satisfy taxes is an administrative step that reduced holdings. The 814-share sale executed under a 10b5-1 plan indicates the sale was pre-planned and not necessarily market-timed. Absolute sizes are small relative to typical officer holdings, suggesting limited direct corporate-governance or balance-sheet impact.

Corporate Governance Expert

TL;DR: Transactions appear compliant and procedural: vesting settlement, tax withholding, and a pre-established trading-plan sale.

From a governance perspective, disclosures meet Section 16 requirements and cite Rule 16b-3(e) for tax withholding and Rule 10b5-1 for the sale, which supports an affirmative defense to insider-trading allegations. The filing is signed by an attorney-in-fact, a common practice for timely compliance. No indication of unusual timing or material divestiture is present based on reported share counts and prices.

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 & Princ. Acctg Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/25/2025

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	08/25/2025		M		2(1)	A	$0.0	29,734	D
Common Stock	08/25/2025		F		798(2)	D	$79.22	28,936	D
Common Stock	08/26/2025		S(3)		814	D	$79.1	28,122	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)	08/25/2025		M			2.7201	(1)	(1)	Common Stock	2.7201	$0.0	47.5424	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	08/27/2025
	** 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 Form 4 reports conversion of dividend equivalent rights into 2.7201 shares on 08/25/2025, withholding of 798 shares for taxes at an implied price of $79.22, and a sale of 814 shares on 08/26/2025 at an average price of $79.10.

Were the sales by the WDC officer part of a trading plan?

Yes. The sale of 814 shares on 08/26/2025 was executed pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2025.

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

Following the reported transactions, the reporting person beneficially owned 28,122 shares of WDC.

Why were shares withheld in connection with the vesting?

The filing states 798 shares were withheld to pay the tax obligation arising from the vesting of securities, in accordance with Rule 16b-3(e).

Who signed the Form 4 filing for Gene Zamiska?

The Form 4 was signed by /s/ Sandra Garcia, Attorney-in-Fact for Gene Zamiska on 08/27/2025.