Western Digital (WDC) legal chief trades shares under 10b5-1 plan

Rhea-AI Filing Summary

Western Digital Corp’s Chief Legal Officer and Corporate Secretary, Cynthia L. Tregillis, reported several equity transactions. She sold a total of 438 shares of common stock in open-market sales on February 23–24, 2026 at prices of $281.70 and $283.83, executed under a Rule 10b5-1 trading plan adopted on May 23, 2025. Around the same time, dividend equivalent rights tied to restricted stock units were converted into small amounts of common stock, and 1,353 shares were withheld at $285.52 per share to cover tax obligations. After these transactions, she directly held 134,759 shares of Western Digital common stock.

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).

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)
02/20/2026

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	02/20/2026		M		3(1)	A	$0.0	136,541	D
Common Stock	02/20/2026		F		244(2)	D	$285.52	136,297	D
Common Stock	02/21/2026		M		9(1)	A	$0.0	136,306	D
Common Stock	02/21/2026		F		1,109(2)	D	$285.52	135,197	D
Common Stock	02/23/2026		S(3)		130	D	$283.83	135,067	D
Common Stock	02/24/2026		S(3)		308	D	$281.7	134,759	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)	02/20/2026		M			3.234	(1)	(1)	Common Stock	3.234	$0.0	344.2281	D
Dividend Equivalent Rights	(1)	02/21/2026		M			9.4399	(1)	(1)	Common Stock	9.4399	$0.0	334.7882	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	02/24/2026
	** 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 transactions did WDC executive Cynthia Tregillis report?

Cynthia Tregillis reported selling 438 Western Digital common shares in open-market trades and several equity-related adjustments. These included shares from dividend equivalent rights conversions and shares withheld to satisfy tax obligations tied to vesting restricted stock units.

At what prices did Cynthia Tregillis sell Western Digital (WDC) shares?

She reported open-market sales of Western Digital common stock at $281.70 and $283.83 per share. These sales occurred over two days and were part of a broader set of equity transactions disclosed in the Form 4 filing.

How many Western Digital shares does Cynthia Tregillis hold after these Form 4 trades?

After the reported transactions, Cynthia Tregillis directly holds 134,759 shares of Western Digital common stock. This figure reflects the net impact of the open-market sales, shares issued from derivative conversions, and shares withheld for tax obligations.

Were Cynthia Tregillis’s Western Digital stock sales made under a trading plan?

Yes. The Form 4 states the reported sales were executed under a Rule 10b5-1 trading plan. That plan was adopted on May 23, 2025, providing a pre-arranged framework for selling shares over time.

What are dividend equivalent rights in the WDC Form 4 for Cynthia Tregillis?

Dividend equivalent rights are credits linked to restricted stock units that mirror dividends on common shares. In this case, they were converted into small numbers of Western Digital common shares when the related restricted stock units vested, with a fractional amount settled in cash.

Why were some Western Digital shares withheld in Cynthia Tregillis’s Form 4?

The filing shows 1,353 shares of Western Digital common stock were withheld at $285.52 per share. These dispositions were used to pay tax obligations associated with the vesting of equity awards, consistent with Rule 16b-3(e).