STX Form 4: William Mosley Sells 20,000 Shares Under 10b5-1 Plan

Q: What did William D. Mosley report on the Form 4 for STX?

The Form 4 reports 22 open-market sales of Seagate ordinary shares on 10/01/2025 , executed under a Rule 10b5-1 plan adopted on February 20, 2025 .

Q: How many Seagate (STX) shares did the reporting person sell?

The filing lists sales totaling 20,000 shares across the reported transactions.

Q: How many Seagate shares does the reporting person own after these transactions?

The Form 4 shows the reporting person beneficially owned 485,668 ordinary shares following the last reported trade.

Q: Was the Form 4 filing single-person or joint?

The form is marked as filed by one reporting person .

Filing Impact

(Very High)

Filing Sentiment

(Negative)

Form Type

Rhea-AI Filing Summary

William D. Mosley, who is listed as a Director and CEO of Seagate Technology Holdings plc (STX), reported multiple open-market sales of ordinary shares on 10/01/2025 under a Rule 10b5-1 trading plan adopted on February 20, 2025. The Form 4 lists 22 separate sale entries totaling 20,000 shares sold at weighted-average prices for each lot. The reported sale prices across the transactions range from a weighted average near $234 up to $258.15, and the explanatory notes state execution price ranges from $233.76 to $258.15. Following the last reported trade, the filings show the reporting person beneficially owned 485,668 ordinary shares.

Positive

Sales executed under a Rule 10b5-1 trading plan adopted on February 20, 2025
Detailed price ranges disclosed (execution ranges and weighted-average prices for each lot)

Negative

Director and CEO sold a total of 20,000 shares in open-market transactions on 10/01/2025
Beneficial ownership decreased to 485,668 ordinary shares following the reported transactions

Insights

TL;DR: CEO/Director sold 20,000 shares on 10/01/2025 under a 10b5-1 plan.

The Form 4 confirms the trades were executed pursuant to a Rule 10b5-1 trading plan adopted on February 20, 2025, which indicates the sales were preplanned rather than reactive to contemporaneous private information.

The filing lists 22 sale transactions on 10/01/2025 with weighted-average prices per lot reported and execution price ranges spanning $233.76 to $258.15. After these transactions the reporting person is shown as holding 485,668 shares.

Insider Trade Summary

Net Seller: 20,000 shares ($4,997,981)

Net Sell 21 txns

Insider MOSLEY WILLIAM D

Role CEO

Sold 20,000 shs ($5.00M)

Type	Security	Shares	Price	Value
Sale	Ordinary Shares	600	$234.0867	$140K
Sale	Ordinary Shares	200	$235.24	$47K
Sale	Ordinary Shares	400	$236.375	$95K
Sale	Ordinary Shares	500	$237.826	$119K
Sale	Ordinary Shares	300	$238.7967	$72K
Sale	Ordinary Shares	500	$240.0192	$120K
Sale	Ordinary Shares	400	$241.50	$97K
Sale	Ordinary Shares	500	$243.428	$122K
Sale	Ordinary Shares	1,400	$245.24	$343K
Sale	Ordinary Shares	1,400	$245.9393	$344K
Sale	Ordinary Shares	700	$247.1986	$173K
Sale	Ordinary Shares	800	$248.3014	$199K
Sale	Ordinary Shares	1,500	$249.416	$374K
Sale	Ordinary Shares	1,004	$250.43	$251K
Sale	Ordinary Shares	700	$252.0314	$176K
Sale	Ordinary Shares	800	$252.4525	$202K
Sale	Ordinary Shares	1,900	$253.7628	$482K
Sale	Ordinary Shares	500	$254.65	$127K
Sale	Ordinary Shares	1,011	$255.6897	$259K
Sale	Ordinary Shares	3,885	$256.8806	$998K
Sale	Ordinary Shares	1,000	$257.827	$258K

Holdings After Transaction: Ordinary Shares — 505,068 shares (Direct)

Footnotes (1)

All transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 20, 2025. These Ordinary Shares were sold in multiple trades at prices ranging from $233.76 to $234.40. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $234.91 to $235.57. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $236.09 to $236.73. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $237.45 to $238.41. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $238.67 to $238.91. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $239.73 to $240.24. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $241.08 to $241.70. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $242.99 to $243.88. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $244.60 to $245.59. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $245.60 to $246.40. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $246.76 to $247.66. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $247.86 to $248.84. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $248.91 to $249.82. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $249.94 to $250.89. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $251.27 to $252.23. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $252.34 to $252.67. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $253.38 to $254.23. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $254.40 to $254.95. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $255.49 to $256.38. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $256.50 to $257.36. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected. These Ordinary Shares were sold in multiple trades at prices ranging from $257.56 to $258.15. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

Form 4 Insider Transactions: What Each Field Means →

10/03/2025 - 04:08 PM

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

MOSLEY WILLIAM D

(Last)

(First)

(Middle)

SEAGATE TECHNOLOGY HOLDINGS PLC

47488 KATO ROAD

(Street)

FREMONT

94538

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
Seagate Technology Holdings plc [ STX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	CEO

3. Date of Earliest Transaction (Month/Day/Year)
10/01/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Ordinary Shares	10/01/2025		S		600⁽¹⁾	D	$234.0867⁽²⁾	505,068	D
Ordinary Shares	10/01/2025		S		200	D	$235.24⁽³⁾	504,868	D
Ordinary Shares	10/01/2025		S		400	D	$236.375⁽⁴⁾	504,468	D
Ordinary Shares	10/01/2025		S		500	D	$237.826⁽⁵⁾	503,968	D
Ordinary Shares	10/01/2025		S		300	D	$238.7967⁽⁶⁾	503,668	D
Ordinary Shares	10/01/2025		S		500	D	$240.0192⁽⁷⁾	503,168	D
Ordinary Shares	10/01/2025		S		400	D	$241.5⁽⁸⁾	502,768	D
Ordinary Shares	10/01/2025		S		500	D	$243.428⁽⁹⁾	502,268	D
Ordinary Shares	10/01/2025		S		1,400	D	$245.24⁽¹⁰⁾	500,868	D
Ordinary Shares	10/01/2025		S		1,400	D	$245.9393⁽¹¹⁾	499,468	D
Ordinary Shares	10/01/2025		S		700	D	$247.1986⁽¹²⁾	498,768	D
Ordinary Shares	10/01/2025		S		800	D	$248.3014⁽¹³⁾	497,968	D
Ordinary Shares	10/01/2025		S		1,500	D	$249.416⁽¹⁴⁾	496,468	D
Ordinary Shares	10/01/2025		S		1,004	D	$250.43⁽¹⁵⁾	495,464	D
Ordinary Shares	10/01/2025		S		700	D	$252.0314⁽¹⁶⁾	494,764	D
Ordinary Shares	10/01/2025		S		800	D	$252.4525⁽¹⁷⁾	493,964	D
Ordinary Shares	10/01/2025		S		1,900	D	$253.7628⁽¹⁸⁾	492,064	D
Ordinary Shares	10/01/2025		S		500	D	$254.65⁽¹⁹⁾	491,564	D
Ordinary Shares	10/01/2025		S		1,011	D	$255.6897⁽²⁰⁾	490,553	D
Ordinary Shares	10/01/2025		S		3,885	D	$256.8806⁽²¹⁾	486,668	D
Ordinary Shares	10/01/2025		S		1,000	D	$257.827⁽²²⁾	485,668	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. All transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 20, 2025.

2. These Ordinary Shares were sold in multiple trades at prices ranging from $233.76 to $234.40. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

3. These Ordinary Shares were sold in multiple trades at prices ranging from $234.91 to $235.57. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

4. These Ordinary Shares were sold in multiple trades at prices ranging from $236.09 to $236.73. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

5. These Ordinary Shares were sold in multiple trades at prices ranging from $237.45 to $238.41. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

6. These Ordinary Shares were sold in multiple trades at prices ranging from $238.67 to $238.91. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

7. These Ordinary Shares were sold in multiple trades at prices ranging from $239.73 to $240.24. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

8. These Ordinary Shares were sold in multiple trades at prices ranging from $241.08 to $241.70. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

9. These Ordinary Shares were sold in multiple trades at prices ranging from $242.99 to $243.88. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

10. These Ordinary Shares were sold in multiple trades at prices ranging from $244.60 to $245.59. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

11. These Ordinary Shares were sold in multiple trades at prices ranging from $245.60 to $246.40. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

12. These Ordinary Shares were sold in multiple trades at prices ranging from $246.76 to $247.66. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

13. These Ordinary Shares were sold in multiple trades at prices ranging from $247.86 to $248.84. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

14. These Ordinary Shares were sold in multiple trades at prices ranging from $248.91 to $249.82. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

15. These Ordinary Shares were sold in multiple trades at prices ranging from $249.94 to $250.89. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

16. These Ordinary Shares were sold in multiple trades at prices ranging from $251.27 to $252.23. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

17. These Ordinary Shares were sold in multiple trades at prices ranging from $252.34 to $252.67. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

18. These Ordinary Shares were sold in multiple trades at prices ranging from $253.38 to $254.23. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

19. These Ordinary Shares were sold in multiple trades at prices ranging from $254.40 to $254.95. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

20. These Ordinary Shares were sold in multiple trades at prices ranging from $255.49 to $256.38. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

21. These Ordinary Shares were sold in multiple trades at prices ranging from $256.50 to $257.36. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

22. These Ordinary Shares were sold in multiple trades at prices ranging from $257.56 to $258.15. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.

Remarks:

	/s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley	10/03/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

Source: View Original Filing on SEC EDGAR

FAQ

What did William D. Mosley report on the Form 4 for STX?

The Form 4 reports 22 open-market sales of Seagate ordinary shares on 10/01/2025, executed under a Rule 10b5-1 plan adopted on February 20, 2025.

How many Seagate (STX) shares did the reporting person sell?

The filing lists sales totaling 20,000 shares across the reported transactions.

At what prices were the STX shares sold in the Form 4?

Weighted-average prices per lot are reported; the explanatory notes show execution price ranges overall from $233.76 to $258.15.

How many Seagate shares does the reporting person own after these transactions?

The Form 4 shows the reporting person beneficially owned 485,668 ordinary shares following the last reported trade.

Was the Form 4 filing single-person or joint?

The form is marked as filed by one reporting person.