Western Digital insider plans sale of 808 shares

Western Digital insider Cynthia Lock Tregillis filed a notice of intent to sell 808 shares of common stock through Morgan Stanley Smith Barney LLC’s Executive Financial Services, with a proposed sale date of July 21, 2026 on NASDAQ.

Rhea-AI Filing Summary

Western Digital insider Cynthia Lock Tregillis filed a notice of intent to sell 808 shares of common stock through Morgan Stanley Smith Barney LLC’s Executive Financial Services, with a proposed sale date of July 21, 2026 on NASDAQ. The shares are reported as Restricted Stock issued by the company. The filing also lists prior sales of Western Digital common stock over the past three months, including transactions on May 21, May 22, May 27, and June 5, 2026, each with specified share counts and dollar values.

Key Figures

Planned shares to be sold: 808 shares Recent sale on June 5, 2026: 432 shares; $235,699.20 Recent sale on May 27, 2026: 214 shares; $115,480.82 +4 more

7 metrics

Planned shares to be sold 808 shares Common stock sale planned on or about July 21, 2026 on NASDAQ

Recent sale on June 5, 2026 432 shares; $235,699.20 Common stock sale by Cynthia Lock Tregillis on June 5, 2026

Recent sale on May 27, 2026 214 shares; $115,480.82 Common stock sale by Cynthia Lock Tregillis on May 27, 2026

Recent sale on May 22, 2026 308 shares; $150,491.88 Common stock sale by Cynthia Lock Tregillis on May 22, 2026

Recent sale on May 21, 2026 106 shares; $48,640.22 Common stock sale by Cynthia Lock Tregillis on May 21, 2026

CUSIP 344682131 Identifier for Western Digital common stock in the Form 144 notice

Share price reference 427,941.04 Figure associated with Western Digital common stock in the broker section

Key Terms

Restricted Stock, Executive Financial Services, CUSIP

3 terms

Restricted Stock financial

"Common | 07/20/2026 | 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.

Executive Financial Services financial

"Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza"

CUSIP financial

"Common | Morgan Stanley Smith Barney LLC ... | 808 | 427941.04 | 344682131"

A CUSIP is a nine-character alphanumeric code that uniquely identifies a U.S. or Canadian financial security—such as a stock, bond, or fund share—like a Social Security number for an investment. It matters to investors because brokers, exchanges and record-keepers use the CUSIP to match trades, track ownership, settle transactions and pull accurate records, reducing errors and ensuring money and securities go to the right place.

FAQ

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

What does the Form 144 filing by WDC insider Cynthia Lock Tregillis report?

The filing reports an intended sale of 808 shares of Western Digital common stock as Restricted Stock through Morgan Stanley Smith Barney LLC on or about July 21, 2026, with trading expected on NASDAQ.

How many Western Digital (WDC) shares is the insider planning to sell?

Cynthia Lock Tregillis plans to sell 808 shares of Western Digital common stock. These shares are classified as Restricted Stock and are to be sold through a broker on NASDAQ around July 21, 2026.

What recent Western Digital (WDC) stock sales are disclosed for Cynthia Lock Tregillis?

The filing lists prior sales of 432 shares for $235,699.20 on June 5, 2026; 214 shares for $115,480.82 on May 27, 2026; 308 shares for $150,491.88 on May 22, 2026; and 106 shares for $48,640.22 on May 21, 2026.

Through which broker will the Western Digital (WDC) insider sale be executed?

The planned sale of 808 shares of Western Digital common stock is designated to be handled by Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, New York, NY 10004.

What type of Western Digital (WDC) security is being sold in this Form 144?

The security is Western Digital Common stock classified as Restricted Stock. The issuer is identified as Western Digital, with trading of the planned sale expected on NASDAQ around July 21, 2026.

Does the Form 144 for Western Digital (WDC) show recent sale proceeds for the insider?

Yes. The filing lists multiple sales, including 432 shares for $235,699.20 on June 5, 2026 and 308 shares for $150,491.88 on May 22, 2026, along with two smaller May 2026 transactions.

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

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Available on EDGAR 07/21/2026 - 04:03 PM Accepted by SEC EDGAR 07/21/2026 - 04:02 PM 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	808	427941.04	344682131	07/21/2026	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	07/20/2026	Restricted Stock	ISSUER			808	07/20/2026	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	06/05/2026	432	235699.20
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	05/27/2026	214	115480.82
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	05/22/2026	308	150491.88
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	05/21/2026	106	48640.22

144: Remarks and Signature

Remarks
Date of Notice	07/21/2026
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)