Western Digital (WDC) Chief Legal Officer reports small pre-planned share sale and tax withholding moves

Rhea-AI Filing Summary

WESTERN DIGITAL CORP Chief Legal Officer Cynthia L. Tregillis reported a small mix of stock transactions. She sold 106 shares of common stock in an open-market sale at $458.87 per share, executed under a pre-arranged Rule 10b5-1 trading plan.

On the same dates, shares were also withheld to cover tax obligations tied to vesting, totaling 1,487 shares treated as F-code tax-withholding dispositions, not open-market sales. She additionally acquired a small number of shares through exercises of dividend equivalent rights. After these transactions, she directly holds 118,443 shares of Western Digital common stock, indicating the sale represents a very small portion of her overall position.

Insights

Insider transactions analyst

Small, pre-planned sale with tax withholding and minor equity accrual; overall routine.

Cynthia L. Tregillis, Chief Legal Officer of WESTERN DIGITAL CORP, executed a modest open-market sale of 106 common shares at $458.87 per share. A footnote states this sale was carried out under a Rule 10b5-1 trading plan adopted on May 23, 2025, indicating the trade was pre-scheduled rather than opportunistic.

In connection with vesting equity awards, 1,487 shares were disposed of as tax-withholding transactions (F-code), which are mechanistic and not market sales. She also exercised dividend equivalent rights, adding a small number of shares. After all transactions, she holds 118,443 common shares directly, so the 106-share sale is a minimal fraction of her position and looks routine in scale.

Insider Trade Summary 10b5-1

Exercise and sale activity reported; no spread calculated

Exercise and Sale 7 txns

Insider Tregillis Cynthia L

Role Chief Legal Officer & Corp Sec

Sold 106 shs ($49K)

Approx. gross sale proceeds $49K

Approx. exercise cost $0.00

Type	Security	Shares	Price	Value
Exercise	Dividend Equivalent Rights	10.5887	$0.00	$0.00
Exercise	Common Stock	10	$0.00	$0.00
Exercise Price or Tax Liability	Common Stock	1,108	$486.46	$539K
Sale	Common Stock	106	$458.87	$49K
Exercise	Dividend Equivalent Rights	3.6301	$0.00	$0.00
Exercise	Common Stock	3	$0.00	$0.00
Exercise Price or Tax Liability	Common Stock	379	$459.62	$174K

Holdings After Transaction: Dividend Equivalent Rights — 318.4089 shares (Direct); Common Stock — 118,443 shares (Direct)

Footnotes (3)

1. F1. 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. F2. Payment of tax obligation by withholding securities incident to the vesting of securities in accordance with Rule 16b-3(e).
3. F3. 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.

Key Figures

Open-market sale: 106 shares at $458.87/share Post-transaction holdings: 118,443 shares Tax-withholding dispositions: 1,487 shares +3 more

6 metrics

Open-market sale 106 shares at $458.87/share Common Stock sale on May 21, 2026

Post-transaction holdings 118,443 shares Directly held common stock after reported trades

Tax-withholding dispositions 1,487 shares F-code shares withheld to pay tax obligations

Dividend equivalent exercise 10.5887 underlying shares Converted dividend equivalent rights on May 21, 2026

Additional derivative exercise 3.6301 underlying shares Dividend equivalent rights converted on May 20, 2026

Additional tax-withholding 379 shares at $459.62/share F-code tax withholding on May 20, 2026

Key Terms

Rule 10b5-1 trading plan, Dividend Equivalent Rights, restricted stock units, tax obligation, +1 more

5 terms

Rule 10b5-1 trading plan regulatory

"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."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

Dividend Equivalent Rights financial

"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..."

Dividend equivalent rights are promises that mirror the cash payments shareholders get from a company’s profits, but they are paid to holders of certain awards (like stock options or restricted stock units) rather than to actual shares. Think of them as a paycheck top‑up that matches dividends while the award is not yet a real stock, and they matter to investors because they add to employee compensation costs and potential share dilution, affecting company profitability and per‑share value.

restricted stock units financial

"in connection with the vesting of restricted stock units to which the dividend equivalent rights relate."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

tax obligation financial

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

Rule 16b-3(e) regulatory

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

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Form 4 Insider Transactions: What Each Field Means →

Accepted by SEC EDGAR 05/22/2026 - 07:24 PM Learn about SEC filing dates

FAQ

What did Western Digital (WDC) insider Cynthia Tregillis do in this Form 4?

Cynthia L. Tregillis reported a small open-market sale of 106 Western Digital common shares and several related equity award transactions, including tax-withholding dispositions and exercises of dividend equivalent rights, while still retaining a sizeable direct holding in the company’s stock.

How many Western Digital shares did Cynthia Tregillis sell and at what price?

She sold 106 shares of Western Digital common stock in an open-market transaction at a reported price of $458.87 per share. This sale was disclosed as part of a broader set of equity-related transactions spanning tax withholding and derivative exercises.

Were Cynthia Tregillis’ Western Digital stock sales under a Rule 10b5-1 plan?

Yes. A footnote states the sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by Cynthia L. Tregillis on May 23, 2025, indicating they were pre-arranged rather than discretionary at the time of sale.

How many Western Digital shares does Cynthia Tregillis hold after these transactions?

Following the reported transactions, Cynthia L. Tregillis directly holds 118,443 shares of Western Digital common stock. This post-transaction holding shows the 106-share open-market sale represents only a very small portion of her overall equity position in the company.

What are the tax-withholding transactions reported for Cynthia Tregillis in WDC stock?

The Form 4 shows F-code transactions where 1,487 Western Digital shares were withheld to satisfy tax obligations tied to vesting securities. These tax-withholding dispositions are not open-market sales; they are automatic mechanisms to cover associated tax liabilities.

What are dividend equivalent rights in Cynthia Tregillis’ Western Digital Form 4?

Dividend equivalent rights are derivative awards that track dividends on underlying shares. The filing explains these rights were converted into, and paid in, Western Digital common stock on a one-for-one basis when related restricted stock units vested, with cash settling a fractional right.

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 CALIFORNIA 95119

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/20/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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	05/20/2026		M		3(1)	A	$0.0	120,026	D
Common Stock	05/20/2026		F		379(2)	D	$459.62	119,647	D
Common Stock	05/21/2026		M		10(1)	A	$0.0	119,657	D
Common Stock	05/21/2026		F		1,108(2)	D	$486.46	118,549	D
Common Stock	05/21/2026		S(3)		106	D	$458.87	118,443	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)	05/20/2026		M			3.6301	(1)	(1)	Common Stock	3.6301	$0.0	328.9976	D
Dividend Equivalent Rights	(1)	05/21/2026		M			10.5887	(1)	(1)	Common Stock	10.5887	$0.0	318.4089	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	05/22/2026
	** 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.
* Form 4: SEC 1474 (03-26)