Western Digital officer plans $305K stock sale

WESTERN DIGITAL CORPORATION (WDC) has an officer, Cynthia Lock Tregillis, filing a Rule 144 notice for a planned sale of 684 shares of Western Digital common stock.

Rhea-AI Filing Summary

WESTERN DIGITAL CORPORATION (WDC) has an officer, Cynthia Lock Tregillis, filing a Rule 144 notice for a planned sale of 684 shares of Western Digital common stock. The proposed sale is through Morgan Stanley Smith Barney LLC Executive Financial Services on 08/24/2026 on NASDAQ.

The shares are described as Restricted Stock. The filing also lists prior sales of Western Digital common stock by Cynthia Lock Tregillis during the past three months, with multiple transactions in May, June, July, and August 2026, each showing the number of shares and aggregate dollar value sold.

Key Figures

Shares proposed to be sold: 684 shares Aggregate market value of proposed sale: $305,180.28 Proposed sale date: 08/24/2026 +4 more

7 metrics

Shares proposed to be sold 684 shares Common stock under Rule 144 for Western Digital Corporation

Aggregate market value of proposed sale $305,180.28 For 684 Western Digital common shares to be sold

Proposed sale date 08/24/2026 Planned Rule 144 sale of Western Digital common stock

Prior sale 1 235 shares for $112,158.45 Common stock sold on 08/21/2026 by Cynthia Lock Tregillis

Prior sale 2 808 shares for $427,941.04 Common stock sold on 07/21/2026 by Cynthia Lock Tregillis

Prior sale 3 432 shares for $235,699.20 Common stock sold on 06/05/2026 by Cynthia Lock Tregillis

Prior sale 4 214 shares for $115,480.82 Common stock sold on 05/27/2026 by Cynthia Lock Tregillis

Key Terms

Rule 144, Restricted Stock, Securities To Be Sold, aggregate market value

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Restricted Stock financial

"Common | 08/21/2026 | Restricted Stock | ISSUER"

Shares granted to an individual that carry limits on transfer or sale until certain conditions are met, such as staying with the company for a set time or hitting performance targets. Think of them as a locked gift that gradually opens; for investors they matter because they affect how many shares may enter the market later, signal management incentives and potential dilution, and reveal confidence in future company performance.

Securities To Be Sold financial

"144: Securities To Be Sold"

aggregate market value financial

"Common | Morgan Stanley... | 684 | 305180.28"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

FAQ

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

What does Western Digital (WDC)'s latest Form 144 filing disclose?

It discloses that officer Cynthia Lock Tregillis has filed a Rule 144 notice to sell 684 shares of Western Digital common stock as Restricted Stock, with a proposed sale date of 08/24/2026 through Morgan Stanley Smith Barney LLC on NASDAQ.

How many Western Digital (WDC) shares are proposed to be sold in this Form 144?

The notice covers a proposed sale of 684 shares of Western Digital common stock. These shares are identified as Restricted Stock to be sold under Rule 144 on or about 08/24/2026 through Morgan Stanley Smith Barney LLC Executive Financial Services.

What is the aggregate market value of the Western Digital (WDC) shares in the planned Rule 144 sale?

The filing lists an aggregate market value of $305,180.28 for the 684 shares of Western Digital common stock covered by the planned Rule 144 sale, with trading intended on NASDAQ on or about 08/24/2026.

Which broker is handling the planned Rule 144 sale for Western Digital (WDC) shares?

The planned sale of 684 shares of Western Digital common stock is to be handled by Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, 8th Floor, New York, NY 10004.

What Western Digital (WDC) stock sales has Cynthia Lock Tregillis made in the past 3 months?

The filing lists four prior sales of Western Digital common stock: 235 shares on 08/21/2026 for $112,158.45, 808 shares on 07/21/2026 for $427,941.04, 432 shares on 06/05/2026 for $235,699.20, and 214 shares on 05/27/2026 for $115,480.82.

Who is the insider in the Western Digital (WDC) Form 144 and what is their role?

The Form 144 is filed for Cynthia Lock Tregillis, identified as an Officer of Western Digital Corporation. The filing covers a planned sale of 684 restricted shares of Western Digital common stock under Rule 144.

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

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Available on EDGAR 08/24/2026 - 04:15 PM EDT Accepted by SEC EDGAR 08/24/2026 - 04:14 PM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0002057088
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	WESTERN DIGITAL CORPORATION
SEC File Number	001-08703
Address of Issuer	5601 Great Oaks Parkway San Jose CALIFORNIA 95119
Phone	(408) 717-6000
Name of Person for Whose Account the Securities are To Be Sold	CYNTHIA LOCK TREGILLIS
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	684	305180.28	360540944	08/24/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/21/2026	Restricted Stock	ISSUER			684	08/21/2026	Not Applicable

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	08/21/2026	235	112158.45
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	07/21/2026	808	427941.04
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	06/05/2026	432	235699.20
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	05/27/2026	214	115480.82

144: Remarks and Signature

Remarks
Date of Notice	08/24/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	03/06/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Cynthia Lock Tregillis
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)