Western Digital (WDC) CLO logs small share sale under 10b5-1 plan

Rhea-AI Filing Summary

Western Digital’s Chief Legal Officer and Corporate Secretary, Cynthia L. Tregillis, reported several equity transactions in company stock. On January 21, 2026, she sold 447 shares of common stock at $229 per share, leaving her with 143,318 common shares held directly. The filing states these sales were made under a Rule 10b5-1 trading plan adopted on May 23, 2025.

On January 20, 2026, dividend equivalent rights tied to restricted stock units were converted on a one-for-one basis into 11 shares of common stock at an exercise price of $0.0. The same day, 842 shares were withheld at $222.97 per share to cover tax obligations upon vesting. After these derivative transactions, she held 347.4621 dividend equivalent rights in addition to her common stock position.

Insider Trade Summary

Net Seller: 447 shares ($102,363)

Net Sell 4 txns

Insider Tregillis Cynthia L

Role Chief Legal Officer & Corp Sec

Sold 447 shs ($102K)

Type	Security	Shares	Price	Value
Sale	Common Stock	447	$229.00	$102K
Exercise	Dividend Equivalent Rights	11.133	$0.00	--
Exercise	Common Stock	11	$0.00	--
Tax Withholding	Common Stock	842	$222.97	$188K

Holdings After Transaction: Common Stock — 143,318 shares (Direct); Dividend Equivalent Rights — 347.462 shares (Direct)

Footnotes (1)

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. Payment of tax obligation by withholding securities incident to the vesting of securities in accordance with Rule 16b-3(e). The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 23, 2025.

Form 4 Insider Transactions: What Each Field Means →

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^*

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)
01/20/2026

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	01/20/2026		M		11(1)	A	$0.0	144,607	D
Common Stock	01/20/2026		F		842(2)	D	$222.97	143,765	D
Common Stock	01/21/2026		S(3)		447	D	$229	143,318	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)	01/20/2026		M			11.1326	(1)	(1)	Common Stock	11.1326	$0.0	347.4621	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 May 23, 2025.

	By: /s/ Sandra Garcia Attorney-in-Fact For: Cynthia Tregillis	01/21/2026
	** 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 transaction did WDC’s Cynthia Tregillis report?

Cynthia L. Tregillis, Chief Legal Officer & Corporate Secretary of Western Digital, reported selling 447 shares of common stock on January 21, 2026 at $229 per share.

How many Western Digital (WDC) shares does Cynthia Tregillis hold after the Form 4?

After the reported transactions, Cynthia Tregillis beneficially owned 143,318 shares of Western Digital common stock directly, plus 347.4621 dividend equivalent rights.

Was the WDC insider sale by Cynthia Tregillis under a Rule 10b5-1 plan?

Yes. The filing states the sales reported were effected pursuant to a Rule 10b5-1 trading plan adopted by Cynthia Tregillis on May 23, 2025.

What are the dividend equivalent rights mentioned in the WDC Form 4?

The filing explains that dividend equivalent rights were converted into, and paid in the form of, shares of Western Digital common stock on a one-for-one basis when related restricted stock units vested, with a cash payment for any fractional right.

Why were 842 WDC shares withheld from Cynthia Tregillis on January 20, 2026?

The Form 4 notes that 842 shares of Western Digital common stock were withheld at $222.97 per share to pay tax obligations incident to the vesting of securities in accordance with Rule 16b-3(e).

What positions does Cynthia Tregillis hold at Western Digital (WDC)?

In the filing, Cynthia L. Tregillis is identified as an officer of Western Digital, serving as Chief Legal Officer & Corporate Secretary.