Seagate (STX) Form 144: William Mosley Plans 20,000-Share Sale

Rhea-AI Filing Summary

Seagate Technology Holdings PLC (STX) Form 144 notifies of a proposed sale by WILLIAM MOSLEY of 20,000 common shares through Morgan Stanley Smith Barney on 09/02/2025, with an aggregate market value listed as $3,348,000.00. The shares were originally acquired as Performance Stock Units on 09/27/2019. The filing also lists four 10b5-1 sales during June–August 2025 totaling 144,347 shares with gross proceeds shown for each transaction. The filer certifies no undisclosed material adverse information and references Rule 10b5-1 procedures.

Positive

• Use of Rule 144 and 10b5-1 mechanisms indicates a structured, preplanned approach to insider sales
• Original acquisition as Performance Stock Units on 09/27/2019 shows the shares were earned, not newly purchased or gifted

Negative

• Insider sales totaling 144,347 shares in June–August 2025 plus the planned 20,000-share sale represent meaningful insider liquidity
• Filing does not display an explicit 10b5-1 plan adoption date within the visible remarks, reducing clarity on trading-plan timing

Insights

Financial Analyst

TL;DR: Insider is liquidating a meaningful block via Rule 144 and 10b5-1 sales; impact appears routine, not company-changing.

The planned 20,000-share sale and prior 144,347 shares sold over three months represent insider liquidity rather than operational news. Proceeds per trade range from ~$2.89M to ~$7.08M, indicating sizeable but not systemic disposal relative to 212,677,178 shares outstanding. Because proceeds are distributed across dated plan sales and the shares originated as 2019 PSUs, this behavior is consistent with post-vesting diversification rather than a reaction to new company developments. Investors should note timing and cumulative volume but the filing itself contains no performance or forward-looking information.

Compliance/Risk Analyst

TL;DR: Documentation shows reliance on Rule 144 and 10b5-1 frameworks; no red flags in the notice but plan dates are not fully detailed.

The filing properly identifies broker, share class, acquisition date, and past 10b5-1 sales with gross proceeds, and includes the required attestation about material nonpublic information. However, the filing does not explicitly state the 10b5-1 plan adoption date within the visible remarks section, which is useful for compliance traceability. From a regulatory perspective, the notice appears procedurally standard but would benefit from explicit plan adoption/instruction dates to fully substantiate the 10b5-1 defense.

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
Filer CCC
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

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

Relationship to Issuer

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	20000	3348000.00	212677178	09/02/2025	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	09/27/2019	Performance Stock Units	Issuer			20000	09/27/2019	N/A

* 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
10b5-1 Sales for WILLIAM MOSLEY 121 Woodlands Avenue 5 Singapore U0 739009	Common	08/01/2025	20000	3074962.00
10b5-1 Sales for WILLIAM MOSLEY 121 Woodlands Avenue 5 Singapore U0 739009	Common	07/01/2025	20000	2893120.00
10b5-1 Sales for WILLIAM MOSLEY 121 Woodlands Avenue 5 Singapore U0 739009	Common	06/09/2025	54347	7075425.06
10b5-1 Sales for WILLIAM MOSLEY 121 Woodlands Avenue 5 Singapore U0 739009	Common	06/03/2025	50000	6013555.00

144: Remarks and Signature

Remarks

Date of Notice

Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1

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

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What did the Form 144 filed for STX disclose about the planned sale?

The Form 144 shows a proposed sale of 20,000 common shares via Morgan Stanley on 09/02/2025 with an aggregate market value of $3,348,000.00.

Who is the filer selling shares in the STX Form 144?

The filer named in past-sales rows is WILLIAM MOSLEY, with sales reported from an address in Singapore; the planned sale is for his account.

When were the shares to be sold originally acquired?

The 20,000 shares listed for sale were acquired as Performance Stock Units on 09/27/2019.

How many shares were sold in the prior three months per this filing?

The filing lists four 10b5-1 sales in June–August 2025 totaling 144,347 shares with gross proceeds shown for each transaction.

Does the filing state whether the seller knows any material nonpublic information?

Yes, the filing includes the seller's representation that they do not know any material adverse information about the issuer that has not been publicly disclosed.