WDC Form 144: Insider resale notice

Regulation 144 notice reporting proposed sales of common stock related to WDC.

Rhea-AI Filing Summary

Regulation 144 notice reporting proposed sales of common stock related to WDC. The filing identifies Cynthia Lock Tregillis as a selling party and lists multiple recent transactions: 02/26/2026 sale of 214 shares for $61,227.54, 02/24/2026 sale of 308 shares for $86,763.60, 02/23/2026 sale of 130 shares for $36,897.90, 02/06/2026 sale of 6,780 shares for $1,833,922.20, and 01/21/2026 sale of 447 shares for $102,363.00.

The broker/filing agent is shown as Morgan Stanley Smith Barney LLC Executive Financial Services. The form lists Restricted Stock dated 03/03/2026 under "Securities To Be Sold."

Insights

Securities Compliance Analyst

Form 144 documents proposed resale activity by an insider-affiliated holder and records prior open-market sales.

The filing lists the selling party as Cynthia Lock Tregillis and shows recent open-market dispositions including $1,833,922.20 on 02/06/2026. It also identifies restricted stock dated 03/03/2026 as the security type for the announced sale.

Regulation 144 notices are administrative disclosures; actual sales depend on compliance with statutory holding periods and broker procedures. Subsequent filings or transfer confirmations would show completed transactions and cash‑flow recipients.

FAQ

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

What does the WDC Form 144 filing state?

The filing states a Regulation 144 resale notice involving Cynthia Lock Tregillis and Morgan Stanley Smith Barney LLC, listing recent sales of common stock including 6,780 shares sold for $1,833,922.20 on 02/06/2026.

Who is the selling party named in the WDC Form 144?

The selling party named is Cynthia Lock Tregillis. The form lists her address and multiple recent transactions, with sales on dates including 01/21/2026 through 02/26/2026 and corresponding proceeds.

What recent sales are disclosed on the Form 144 for WDC?

Recent disclosed sales include 214 shares for $61,227.54 on 02/26/2026, 308 shares for $86,763.60 on 02/24/2026, and 6,780 shares for $1,833,922.20 on 02/06/2026.

Does the Form 144 show who receives the proceeds from the sales?

The filing lists the broker as Morgan Stanley Smith Barney LLC Executive Financial Services but does not state the ultimate proceeds recipient explicitly beyond identifying the selling party, Cynthia Lock Tregillis, and transaction amounts.

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

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Accepted by SEC EDGAR 03/04/2026 - 04:04 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	777	200396.07	339037922	03/04/2026	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	03/03/2026	Restricted Stock	ISSUER			777	03/03/2026	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	02/26/2026	214	61227.54
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	02/24/2026	308	86763.60
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	02/23/2026	130	36897.90
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	02/06/2026	6780	1833922.20
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	01/21/2026	447	102363.00

144: Remarks and Signature

Remarks
Date of Notice	03/04/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	05/23/2025
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)