[Form 4] Western Digital Corp. Insider Trading Activity

Rhea-AI Filing Summary

Cynthia Tregillis, Chief Legal Officer & Corporate Secretary of Western Digital Corporation (WDC), reported equity awards and withholding related to vesting. On 08/26/2025 she was granted 16,554 restricted stock units that vest into common stock. On 08/27/2025 dividend equivalent rights tied to those RSUs were converted into shares on a one-for-one basis and 1.1421 dividend-equivalent shares were recorded. Also on 08/27/2025, 266 shares were withheld to satisfy tax obligations at an indicated price of $80.67, leaving 150,874 shares beneficially owned after the transactions.

Positive

• 16,554 restricted stock units granted, increasing the reporting person's alignment with shareholders
• Dividend equivalent rights converted into shares on a one-for-one basis, preserving equity value for the holder
• Timely Form 4 disclosure with reporting person role and transaction details provided

Negative

• 266 shares withheld to satisfy tax obligations, reducing the reporting person's net shareholding
• Withholding executed at $80.67, reflecting a taxable event realized at that price

Insights

Securities Compliance Analyst

TL;DR: Routine equity compensation and tax withholding by an insider; disclosures align with standard Section 16 reporting.

The Form 4 shows a grant of 16,554 RSUs, conversion of related dividend equivalent rights into shares, and withholding of 266 shares to satisfy taxes at $80.67 per share. Reporting is consistent with compensation vesting events and Rule 16b-3 mechanics. All transactions are reported within the required timeframe and the filing identifies the reporting person and her officer role.

Corporate Governance Specialist

TL;DR: Insider equity vesting increases alignment; withholding to cover taxes is a common, non-material disposition.

The RSU grant and the conversion of dividend equivalents are typical elements of executive compensation. The withholding of 266 shares reduces net share count but is described as tax withholding incident to vesting. The filing includes an attorney-in-fact signature, indicating the report was executed on behalf of the reporting person.

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

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

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^*

Tregillis Cynthia L

(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)
	Chief Legal Officer & Corp Sec

3. Date of Earliest Transaction (Month/Day/Year)
08/26/2025

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(1)	08/26/2025		A		16,554	A	$0.0	151,139	D
Common Stock	08/27/2025		M		1(2)	A	$0.0	151,140	D
Common Stock	08/27/2025		F		266(3)	D	$80.67	150,874	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	(2)	08/27/2025		M			1.1421	(2)	(2)	Common Stock	1.1421	$0.0	181.8051	D

Explanation of Responses:

1. 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.

2. 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.

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

	By: /s/ Sandra Garcia Attorney-in-Fact For: Cynthia Tregillis	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

Who filed this Form 4 for WDC and what is their role?

The filing was made by Cynthia Tregillis, who is identified as Chief Legal Officer & Corporate Secretary of Western Digital Corporation.

How many restricted stock units were granted to the reporting person?

The Form 4 reports a grant of 16,554 restricted stock units on 08/26/2025.

Were any shares disposed of or withheld and at what price?

Yes, 266 shares were withheld to satisfy tax obligations in connection with vesting, at an indicated price of $80.67.

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

After the reported transactions the filing shows 150,874 shares beneficially owned.

What happened to dividend equivalent rights related to the RSUs?

The dividend equivalent rights were converted into and paid in the form of shares on a one-for-one basis in connection with the vesting of the RSUs; a cash payment settled any fractional share.