Western Digital officer plans $195K stock sale

An executive of WESTERN DIGITAL CORP has filed to sell 432 common shares under Rule 144, following several stock sales in prior months.

Rhea-AI Filing Summary

WESTERN DIGITAL CORP (WDC) has a notice from officer Cynthia Lock Tregillis to sell common stock under Rule 144. The planned sale covers 432 shares of common stock held in an account at Morgan Stanley Smith Barney LLC Executive Financial Services.

Over the prior three months, Cynthia Lock Tregillis reported multiple sales of Western Digital common stock, including 432 shares on June 5, 2026; 808 shares on July 21, 2026; and several transactions in August 2026.

Key Figures

Shares to be sold: 432 shares Aggregate market value for current notice: $194,918.40 Shares sold on June 5, 2026: 432 shares +5 more

8 metrics

Shares to be sold 432 shares Common stock of Western Digital subject to the current Rule 144 notice

Aggregate market value for current notice $194,918.40 Aggregate market value associated with the 432 shares to be sold

Shares sold on June 5, 2026 432 shares Common stock sale during the past 3 months

Proceeds on June 5, 2026 $235,699.20 Total value reported for the June 5, 2026 sale

Shares sold on July 21, 2026 808 shares Common stock sale during the past 3 months

Proceeds on July 21, 2026 $427,941.04 Total value reported for the July 21, 2026 sale

Largest single recent sale 1,007 shares Western Digital common stock sold on August 27, 2026

Proceeds from August 27, 2026 sale $481,708.52 Total value reported for 1,007 shares sold on August 27, 2026

Key Terms

Rule 144, restricted stock, aggregate market value

3 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 | 09/03/2026 | 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.

aggregate market value financial

"Common | Morgan Stanley Smith Barney LLC Executive Financial Services ... | 432 | 194918.40"

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 the Form 144 for WESTERN DIGITAL CORP (WDC) disclose?

It discloses that Cynthia Lock Tregillis, an officer of Western Digital, has filed a notice under Rule 144 to sell 432 shares of Western Digital common stock through a brokerage account.

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

The notice covers a proposed sale of 432 shares of Western Digital common stock. These shares are held in an account at Morgan Stanley Smith Barney LLC Executive Financial Services and are to be sold under Rule 144.

What type of securities are involved in the WESTERN DIGITAL (WDC) Form 144?

The securities are common stock of Western Digital Corporation. The Form 144 identifies the securities to be sold as restricted stock of the issuer, Western Digital Corporation.

Who is the reporting person in this WESTERN DIGITAL (WDC) Form 144?

The reporting person is Cynthia Lock Tregillis, identified as an officer of Western Digital Corporation. The notice relates to sales for her account and any others required to be aggregated under Rule 144.

What Western Digital (WDC) stock sales occurred in the past 3 months for this person?

In the past 3 months, Cynthia Lock Tregillis reported multiple Western Digital common stock sales, including 432 shares on June 5, 2026; 808 shares on July 21, 2026; and several August 2026 transactions of 235–1,007 shares each.

On what market are the WESTERN DIGITAL (WDC) shares in this Form 144 listed?

The notice identifies the Western Digital common stock to be sold as listed on NASDAQ. The planned sale of 432 shares references NASDAQ as the trading market.

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

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Available on EDGAR 09/04/2026 - 04:02 PM EDT Accepted by SEC EDGAR 09/04/2026 - 04:01 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	432	194918.40	360540944	09/04/2026	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	09/03/2026	Restricted Stock	ISSUER			432	09/03/2026	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	08/27/2026	1007	481708.52
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	08/26/2026	476	214571.28
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	08/24/2026	684	305180.28
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

144: Remarks and Signature

Remarks
Date of Notice	09/04/2026
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)