[Form 4] Western Digital Corp. Insider Trading Activity

Rhea-AI Filing Summary

Gene M. Zamiska, SVP & Principal Accounting Officer of Western Digital Corp. (WDC), reported insider activity on 08/27/2025–08/28/2025. Dividend equivalent rights were converted into common shares on a one-for-one basis in connection with restricted stock unit vesting, producing an acquisition entry and increasing reported shares received; a fractional dividend equivalent was settled in cash. The filer had 345 shares withheld to satisfy tax obligations related to vesting. Additionally, 353 shares were sold on 08/28/2025 under a Rule 10b5-1 trading plan adopted March 6, 2025. Following these events the reporting person beneficially owned 27,425 shares directly. All transactions are reported as direct ownership.

Positive

• Conversion of dividend equivalents into shares was explicitly reported and settled one-for-one, aligning with compensation plan terms
• Use of a Rule 10b5-1 trading plan for the sale on 08/28/2025 indicates pre-established, compliant disposition procedures
• Tax withholding was executed via share withholding and disclosed, showing administrative compliance with compensation tax obligations
• All transactions reported as direct beneficial ownership, providing clear transparency

Negative

• Reported sell-down of 353 shares on 08/28/2025 reduced the reporting person’s direct holdings
• 345 shares withheld for taxes reduced post-vesting share count

Insights

Securities Analyst

TL;DR: Routine insider vesting, tax withholding, and planned sales; no new material information for valuation.

The Form 4 shows standard equity compensation mechanics: dividend equivalents were converted into shares upon RSU vesting, a portion of shares was withheld to cover taxes, and a scheduled sale under a pre-existing Rule 10b5-1 plan executed. The transactions change the reporting person’s direct share count from prior levels to 27,425 shares but do not disclose company-wide material events, changes in ownership control, or unusual timing that would suggest non-routine activity. Disclosure complies with Section 16 reporting requirements.

Corporate Governance Expert

TL;DR: Properly disclosed compensation settlement and planned disposition; governance procedures (10b5-1, withholding) followed.

The filing documents the conversion of dividend equivalent rights into common stock tied to RSU vesting and a subsequent sale executed through an established Rule 10b5-1 plan. The tax withholding of 345 shares to satisfy tax obligations and the manual signature by an attorney-in-fact indicate administrative compliance. These are routine insider actions that reflect compensation administration rather than governance changes or red flags.

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)
08/27/2025

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	08/27/2025		M		1(1)	A	$0.0	28,123	D
Common Stock	08/27/2025		F		345(2)	D	$80.67	27,778	D
Common Stock	08/28/2025		S(3)		353	D	$80.9	27,425	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)	08/27/2025		M			1.1776	(1)	(1)	Common Stock	1.1776	$0.0	46.3648	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	08/28/2025
	** 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 insider transactions did Gene Zamiska report for WDC on 08/27–08/28/2025?

The Form 4 shows dividend equivalent rights converted into common shares upon RSU vesting, 345 shares withheld for taxes, and a sale of 353 shares on 08/28/2025 under a Rule 10b5-1 plan.

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

Following the reported transactions the filing shows the reporting person directly beneficially owned 27,425 shares of WDC.

Were the sales effected under a trading plan for WDC insider Gene Zamiska?

Yes. The sale of 353 shares on 08/28/2025 was effected pursuant to a Rule 10b5-1 trading plan adopted on March 6, 2025, as disclosed in the Form 4.

Why were shares withheld in the WDC Form 4 filing?

The filing states 345 shares were withheld to pay the tax obligation incident to the vesting of securities, consistent with Rule 16b-3(e).

Did the filing disclose any indirect ownership or third-party arrangements for WDC shares?

No. All reported holdings and transactions are shown as direct (D) ownership in the Form 4; no indirect ownership descriptions were provided.