WDC affiliate files Form 144 to sell restricted shares

Morgan Stanley Smith Barney LLC Executive Financial Services submitted a Form 144 notice for proposed sale of restricted common stock on 05/20/2026 with execution via NASDAQ.

Rhea-AI Filing Summary

Morgan Stanley Smith Barney LLC Executive Financial Services submitted a Form 144 notice for proposed sale of restricted common stock on 05/20/2026 with execution via NASDAQ. The excerpt lists recent sales by Cynthia Lock Tregillis on multiple dates in 2026, showing individual dispositions and dollar amounts.

Insights

Securities Counsel

Form 144 notice records proposed affiliate sales, not a company issuance.

Form 144 is a regulatory notice of proposed resale by an affiliate or control person; it does not itself effect a sale. The excerpt identifies restricted stock listed as "ISSUER" and execution via NASDAQ.

Cash‑flow treatment and proceeds recipient are the selling holder(s). Timing and completion depend on execution in the market and regulatory compliance; subsequent filings will show completed transactions.

Key Figures

Proposed sale date: 05/20/2026 Prior sale (03/04/2026): 9,324 shares Proceeds listed (03/04/2026): $2,501,381.80 +2 more

5 metrics

Proposed sale date 05/20/2026 Form 144 line for restricted common stock

Prior sale (03/04/2026) 9,324 shares Sale by Cynthia Lock Tregillis on <date>03/04/2026</date>

Proceeds listed (03/04/2026) $2,501,381.80 Dollar amount tied to 9,324-share sale on <date>03/04/2026</date>

Prior sale (04/21/2026) 363 shares Sale by Cynthia Lock Tregillis on <date>04/21/2026</date>

Proceeds listed (04/21/2026) $136,883.67 Dollar amount tied to 363-share sale on <date>04/21/2026</date>

Key Terms

Restricted Stock, ISSUER, Form 144

3 terms

Restricted Stock financial

"Common | 05/20/2026 | 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.

ISSUER regulatory

"Restricted Stock | ISSUER | | | 106 | 05/20/2026"

Form 144 regulatory

"Filer Information | 144: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

FAQ

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

What does WDC's Form 144 filing signify?

It notifies the SEC of a proposed resale of restricted common stock by an affiliate. The filing lists a planned sale date of 05/20/2026 and indicates execution on NASDAQ; it does not itself complete any trades.

Who appears to be selling shares in the excerpt?

The excerpt lists recent dispositions by Cynthia Lock Tregillis, including trades dated 04/21/2026, 03/04/2026, and earlier 2026 dates with shares and dollar amounts shown for each sale.

Are the amounts in the filing actual sales or proposed amounts?

The listed dollar amounts and share counts for prior dates reflect sales already reported for the named holder. The Form 144 line dated 05/20/2026 shows the proposed sale of restricted shares by the filer.

Does the filing state who receives the proceeds?

The excerpt does not specify proceeds recipients beyond identifying the selling holder and the entry as "ISSUER" for the securities type. It lists execution via NASDAQ but does not describe use of proceeds.

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

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Accepted by SEC EDGAR 05/21/2026 - 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	106	48640.22	344682131	05/21/2026	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	05/20/2026	Restricted Stock	ISSUER			106	05/20/2026	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	04/21/2026	363	136883.67
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	03/04/2026	9324	2501381.80
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

144: Remarks and Signature

Remarks
Date of Notice	05/21/2026
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)