Western Digital (NASDAQ: WDC) officer plans sale of 235 shares

Rhea-AI Filing Summary

WESTERN DIGITAL CORPORATION (symbol WDC) is the issuer for a notice filed by officer Cynthia Lock Tregillis under Rule 144, indicating an intention to sell 235 shares of common stock. The shares are to be sold through Morgan Stanley Smith Barney LLC Executive Financial Services, with an indicated transaction value of $112,158.45 and listing venue NASDAQ.

The 235 common shares were acquired on 08/20/2026 as Restricted Stock from the issuer. The notice also lists prior sales of Western Digital common stock by Cynthia Lock Tregillis during the past three months, including transactions of 808 shares for $427,941.04 on 07/21/2026, 432 shares for $235,699.20 on 06/05/2026, 214 shares for $115,480.82 on 05/27/2026, and 308 shares for $150,491.88 on 05/22/2026.

Key Figures

Shares to be sold: 235 shares Proposed transaction value: $112,158.45 CUSIP: 360540944 +4 more

7 metrics

Shares to be sold 235 shares Common stock covered by current Rule 144 notice

Proposed transaction value $112,158.45 Value associated with the 235 shares of common stock

CUSIP 360540944 Identifier for Western Digital common stock in the notice

Prior sale 07/21/2026 808 shares; $427,941.04 Common stock sale listed for the past three months

Prior sale 06/05/2026 432 shares; $235,699.20 Common stock sale listed for the past three months

Prior sale 05/27/2026 214 shares; $115,480.82 Common stock sale listed for the past three months

Prior sale 05/22/2026 308 shares; $150,491.88 Common stock sale listed for the past three months

Key Terms

Rule 144, Restricted Stock, CUSIP

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 | 08/20/2026 | 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.

CUSIP financial

"Common | Morgan Stanley Smith Barney LLC ... | 235 | 112158.45 | 360540944"

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

What does the Form 144 filing for WDC disclose about Cynthia Lock Tregillis?

It discloses that officer Cynthia Lock Tregillis filed a Rule 144 notice for the potential sale of 235 shares of Western Digital common stock, acquired as Restricted Stock on 08/20/2026 and to be sold through Morgan Stanley Smith Barney LLC on NASDAQ.

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

The notice covers a proposed sale of 235 shares of Western Digital common stock, with an indicated transaction value of $112,158.45. These shares were acquired on 08/20/2026 as Restricted Stock from Western Digital Corporation.

Which broker is handling the potential Rule 144 sale for WDC stock?

The potential Rule 144 sale for Western Digital (WDC) common stock is listed as being handled by Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, New York, NY 10004.

What prior Western Digital (WDC) stock sales by Cynthia Lock Tregillis are disclosed?

The filing lists four prior common stock sales in the past three months: 808 shares for $427,941.04 on 07/21/2026, 432 shares for $235,699.20 on 06/05/2026, 214 shares for $115,480.82 on 05/27/2026, and 308 shares for $150,491.88 on 05/22/2026.

When were the WDC shares in the new Form 144 acquired and in what form?

The 235 shares of Western Digital common stock covered by the new Form 144 were acquired on 08/20/2026 as Restricted Stock from Western Digital Corporation, according to the issuer and securities information sections.

What is the role of Cynthia Lock Tregillis in relation to Western Digital (WDC)?

Cynthia Lock Tregillis is identified in the filing as an Officer of Western Digital Corporation, and the Form 144 notice relates to transactions in Western Digital common stock for her account.

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

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Available on EDGAR 08/21/2026 - 04:27 PM Accepted by SEC EDGAR 08/21/2026 - 04:27 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	235	112158.45	360540944	08/21/2026	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	08/20/2026	Restricted Stock	Issuer			235	08/20/2026	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	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
CYNTHIA LOCK TREGILLIS 5601 Great Oaks Parkway San Jose CA 95119	Common	05/22/2026	308	150491.88

144: Remarks and Signature

Remarks
Date of Notice	08/21/2026
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)