Western Digital CLO sells stock under 10b5-1 plan

Q: Who is the insider trading WESTERN DIGITAL CORP (WDC) shares in this Form 4?

The reporting person is Cynthia L. Tregillis, who serves as Chief Legal Officer & Corporate Secretary of Western Digital Corp. She reported sales of common stock and related equity award and tax-withholding transactions in this Form 4.

Q: How many WESTERN DIGITAL (WDC) shares did Cynthia Tregillis sell and at what prices?

Cynthia Tregillis reported selling 235 shares of Western Digital common stock at $477.27 per share on August 21, 2026 and 684 shares at $446.17 per share on August 24, 2026, in open-market or private transactions.

Q: What are the Dividend Equivalent Rights mentioned in the WDC Form 4?

The filing describes Dividend Equivalent Rights that were converted into, and paid in the form of, shares of Western Digital common stock on a one-for-one basis in connection with the vesting of the related restricted stock units. A fractional right was settled in cash.

Q: How many WDC shares were withheld to cover the insider’s tax obligations?

The Form 4 reports that 1,109 shares at $459.44 per share and 379 shares at $469.05 per share of Western Digital common stock, totaling 1,488 shares, were withheld to pay tax obligations incident to vesting, under Rule 16b-3(e).

WESTERN DIGITAL CORP (WDC) insider Cynthia L. Tregillis, Chief Legal Officer & Corp Sec, reported multiple equity transactions.

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Rhea-AI Filing Summary

WESTERN DIGITAL CORP (WDC) insider Cynthia L. Tregillis, Chief Legal Officer & Corp Sec, reported multiple equity transactions. On August 21 and 24, 2026 she sold 235 and 684 shares of common stock at $477.27 and $446.17 per share, respectively, with both sales effected pursuant to a Rule 10b5-1 trading plan adopted on March 6, 2026. Around August 20–21, dividend equivalent rights related to restricted stock units were converted into common shares on a one-for-one basis, and a total of 1,488 shares was withheld at prices of $469.05 and $459.44 per share to satisfy tax obligations under Rule 16b-3(e).

Insider Trade Summary 10b5-1

Exercise and sale activity reported; no spread calculated

Exercise and Sale 8 txns

Insider Tregillis Cynthia L

Role Chief Legal Officer & Corp Sec

Sold 919 shs ($417K)

Approx. gross sale proceeds $417K

Type	Security	Shares	Price	Value
Sale	Common Stock ^F3	684	$446.17	$305K
Exercise	Dividend Equivalent Rights ^F1	11.1826	$0.00	$0.00
Sale	Common Stock ^F3	235	$477.27	$112K
Exercise	Common Stock ^F1	11	$0.00	$0.00
Tax Withholding	Common Stock ^F2	1,109	$459.44	$510K
Exercise	Dividend Equivalent Rights ^F1	3.8337	$0.00	$0.00
Exercise	Common Stock ^F1	3	$0.00	$0.00
Tax Withholding	Common Stock ^F2	379	$469.05	$178K

Holdings After Transaction: Dividend Equivalent Rights — 294.7877 contracts (Direct); Common Stock — 112,146 shares (Direct)

Footnotes (3)

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.
F2. Payment of tax obligation by withholding securities incident to the vesting of securities in accordance with Rule 16b-3(e).
F3. 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, 2026.

Key Figures

Common stock sold: 235 shares Sale price per share: $477.27 Common stock sold: 684 shares +5 more

8 metrics

Common stock sold 235 shares Sale of Western Digital common stock on August 21, 2026

Sale price per share $477.27 Sale of 235 shares of common stock on August 21, 2026

Common stock sold 684 shares Sale of Western Digital common stock on August 24, 2026

Sale price per share $446.17 Sale of 684 shares of common stock on August 24, 2026

Shares withheld for taxes 1,109 shares Tax withholding at $459.44 per share incident to vesting

Shares withheld for taxes 379 shares Tax withholding at $469.05 per share incident to vesting

Dividend Equivalent Rights converted 11.1826 rights Converted into common stock on a one-for-one basis on August 21, 2026

Dividend Equivalent Rights converted 3.8337 rights Converted into common stock on a one-for-one basis on August 20, 2026

Key Terms

Rule 10b5-1 trading plan, Dividend Equivalent Rights, restricted stock units, Rule 16b-3(e)

4 terms

Rule 10b5-1 trading plan regulatory

"The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan"

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"

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.

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)"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

Who is the insider trading WESTERN DIGITAL CORP (WDC) shares in this Form 4?

The reporting person is Cynthia L. Tregillis, who serves as Chief Legal Officer & Corporate Secretary of Western Digital Corp. She reported sales of common stock and related equity award and tax-withholding transactions in this Form 4.

How many WESTERN DIGITAL (WDC) shares did Cynthia Tregillis sell and at what prices?

Cynthia Tregillis reported selling 235 shares of Western Digital common stock at $477.27 per share on August 21, 2026 and 684 shares at $446.17 per share on August 24, 2026, in open-market or private transactions.

Were the WDC insider sales made under a Rule 10b5-1 trading plan?

Yes. A footnote states that the sales reported were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2026, indicating the trades were pre-arranged under that plan.

What are the Dividend Equivalent Rights mentioned in the WDC Form 4?

The filing describes Dividend Equivalent Rights that were converted into, and paid in the form of, shares of Western Digital common stock on a one-for-one basis in connection with the vesting of the related restricted stock units. A fractional right was settled in cash.

How many WDC shares were withheld to cover the insider’s tax obligations?

The Form 4 reports that 1,109 shares at $459.44 per share and 379 shares at $469.05 per share of Western Digital common stock, totaling 1,488 shares, were withheld to pay tax obligations incident to vesting, under Rule 16b-3(e).

Did Cynthia Tregillis acquire any WESTERN DIGITAL (WDC) shares in this Form 4?

Yes. On August 20 and 21, 2026, she reported acquiring small amounts of Western Digital common stock through the conversion of Dividend Equivalent Rights related to vested restricted stock units, at a stated price of $0.00 per share.

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Available on EDGAR 08/24/2026 - 07:00 PM EDT Accepted by SEC EDGAR 08/24/2026 - 07:00 PM EDT

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).

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)
08/20/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	08/20/2026		M		3⁽¹⁾	A	$0.0	114,542	D
Common Stock	08/20/2026		F		379⁽²⁾	D	$469.05	114,163	D
Common Stock	08/21/2026		S⁽³⁾		235	D	$477.27	113,928	D
Common Stock	08/21/2026		M		11⁽¹⁾	A	$0.0	113,939	D
Common Stock	08/21/2026		F		1,109⁽²⁾	D	$459.44	112,830	D
Common Stock	08/24/2026		S⁽³⁾		684	D	$446.17	112,146	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Dividend Equivalent Rights	⁽¹⁾	08/20/2026		M			3.8337	⁽¹⁾	⁽¹⁾	Common Stock	3.8337	$0.0	305.9703	D
Dividend Equivalent Rights	⁽¹⁾	08/21/2026		M			11.1826	⁽¹⁾	⁽¹⁾	Common Stock	11.1826	$0.0	294.7877	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, 2026.

	By: /s/ Sandra Garcia Attorney-in-Fact For: Cynthia Tregillis	08/24/2026
	** 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.
* Form 4: SEC 1474 (03-26)

Source: View Original Filing on SEC EDGAR