Western Digital officer plans sale of 476 shares

WESTERN DIGITAL CORPORATION (WDC) received a Rule 144 notice from officer Cynthia Lock Tregillis covering a proposed sale of 476 shares of common stock through Morgan Stanley Smith Barney LLC Executive Financial Services on NASDAQ.

Rhea-AI Filing Summary

WESTERN DIGITAL CORPORATION (WDC) received a Rule 144 notice from officer Cynthia Lock Tregillis covering a proposed sale of 476 shares of common stock through Morgan Stanley Smith Barney LLC Executive Financial Services on NASDAQ. The notice also lists prior sales of WDC common stock over the past three months, including 684 shares on August 24, 2026 and 808 shares on July 21, 2026.

Key Figures

Shares to be sold: 476 shares Shares sold 08/24/2026: 684 shares Shares sold 08/21/2026: 235 shares +3 more

6 metrics

Shares to be sold 476 shares Proposed sale of WESTERN DIGITAL CORP common stock under Rule 144

Shares sold 08/24/2026 684 shares Sale of WESTERN DIGITAL CORP common stock during the past 3 months

Shares sold 08/21/2026 235 shares Sale of WESTERN DIGITAL CORP common stock during the past 3 months

Shares sold 07/21/2026 808 shares Sale of WESTERN DIGITAL CORP common stock during the past 3 months

Shares sold 06/05/2026 432 shares Sale of WESTERN DIGITAL CORP common stock during the past 3 months

Shares sold 05/27/2026 214 shares Sale of WESTERN DIGITAL CORP common stock during the past 3 months

Key Terms

Rule 144, Restricted Stock, Securities To Be Sold, Securities Sold During The Past 3 Months

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 | 08/25/2026 | 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"

Securities Sold During The Past 3 Months financial

"144: Securities Sold During The Past 3 Months"

FAQ

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

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

The filing states that officer Cynthia Lock Tregillis has filed a Rule 144 notice for a proposed sale of 476 shares of WESTERN DIGITAL CORP common stock through Morgan Stanley Smith Barney LLC Executive Financial Services on NASDAQ.

How many WDC shares are covered by the new Rule 144 notice?

The notice covers a proposed sale of 476 shares of WESTERN DIGITAL CORP common stock, shown in the section describing the securities information and the securities to be sold.

Who is the insider selling WESTERN DIGITAL CORP (WDC) shares under Rule 144?

The insider is Cynthia Lock Tregillis, identified as an officer of WESTERN DIGITAL CORP. The Form 144 lists her as the person for whose account the WDC common stock is to be sold.

Which broker is handling the proposed WDC share sale on this Form 144?

The proposed sale of WESTERN DIGITAL CORP common stock is listed through Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, 8th Floor, New York, NY 10004.

What WDC stock sales by Cynthia Lock Tregillis are disclosed for the past 3 months?

The filing lists several sales of WESTERN DIGITAL CORP common stock, including 684 shares on August 24, 2026, 235 shares on August 21, 2026, 808 shares on July 21, 2026, 432 shares on June 5, 2026, and 214 shares on May 27, 2026.

What type of WDC security is being sold under this Form 144?

The notice relates to sales of common stock of WESTERN DIGITAL CORP. The securities to be sold section also notes the security as Restricted Stock with the issuer listed as the source.

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

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 08/26/2026 - 04:03 PM EDT Accepted by SEC EDGAR 08/26/2026 - 04:02 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	476	214571.28	360540944	08/26/2026	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	08/25/2026	Restricted Stock	ISSUER			476	08/25/2026	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	08/24/2026	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
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	08/26/2026
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)