[Form 4] Seagate Technology Holdings plc Insider Trading Activity

Rhea-AI Filing Summary

William D. Mosley, CEO and Director of Seagate Technology Holdings plc (STX), reported several equity transactions in a Form 4 filed for the period surrounding September 11–14, 2025. The filing shows awards and vesting of restricted share units and performance-based restricted share units, plus related disposals.

The report records acquisitions of 3,319 ordinary shares on 09/11/2025 and 65,170 ordinary shares on 09/14/2025, tied to restricted share units and performance share units that vested. Offsetting disposals total 34,609 shares (1,678 shares disposed at $196.81 on 09/11/2025 and 32,931 shares disposed at $195.99 on 09/14/2025). Following the reported transactions, Mosley beneficially owned 538,599 ordinary shares.

Positive

• Significant vesting of performance-based restricted share units: 65,170 shares vested on 09/14/2025 after performance conditions were met
• Increased beneficial ownership to 538,599 ordinary shares following the reported transactions

Negative

• Executed disposals of 34,609 shares (1,678 at $196.81 and 32,931 at $195.99), reducing immediately held shares

Insights

Corporate Governance Expert

TL;DR: CEO received vesting of long-term equity awards while selling a portion of shares; ownership increased materially.

The filing documents routine compensation-related activity: restricted share units and performance-based restricted share units vested and converted into ordinary shares, increasing the reporting person's holdings to 538,599 shares. Concurrent disposals of 34,609 shares occurred at market prices near $196, consistent with typical post-vesting sales for liquidity or tax obligations. The Compensation Committee certified performance conditions for a majority of the 2022 grant, resulting in 65,170 vested shares.

Securities Analyst

TL;DR: Material vesting added 65,170 shares; net position rose, while planned sales reduced a portion of the new shares.

From an investor-disclosure perspective, the transaction mix is significant in size but aligned with equity compensation mechanics: a large tranche of performance share units vested on 09/14/2025, adding 65,170 shares to beneficial ownership. Sales of ~34.6k shares were executed at ~$196 per share on two dates, leaving a higher post-transaction holding. This filing is informative about executive compensation realization but contains no indication of change in corporate control or extraordinary events.

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

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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 CA 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)
09/11/2025

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)
			Code	V	Amount	(A) or (D)	Price
Ordinary Shares	09/11/2025		M		3,319	A	$0	475,107	D
Ordinary Shares	09/11/2025		F		1,678	D	$196.81	473,429	D
Ordinary Shares	09/14/2025		M		65,170	A	$0	538,599	D
Ordinary Shares	09/14/2025		F		32,931	D	$195.99	505,668	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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Restricted Share Unit	$0	09/11/2025		M			3,319	(1)	(1)	Ordinary Shares	3,319	$0	26,552	D
Performance-Based Restricted Share Units	$0	09/14/2025		A		65,170		(2)	(2)	Ordinary Shares	65,170	$0	65,170	D
Performance-Based Restricted Share Units	$0	09/14/2025		M			65,170	(2)	(2)	Ordinary Shares	65,170	$0	0	D

Explanation of Responses:

1. Consists of a grant of restricted share units awarded to the reporting person under the Seagate Technology plc 2022 Equity Incentive Plan. Subject to the Reporting Person's continuous employment, one-quarter vested starting on September 11, 2024 and then in equal quarterly installments over the following three years for a total vesting period of four years.

2. On September 14, 2025, the Compensation Committee of the Board of Directors of the Issuer determined that the performance conditions were met with respect to 65,170 of the 75,045 Performance Share Units granted on September 9, 2022. The 65,170 Ordinary Shares vested on September 14, 2025.

Remarks:

	/s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley	09/15/2025
	** 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.

FAQ

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

The Form 4 reports acquisitions of 3,319 shares on 09/11/2025 and 65,170 shares on 09/14/2025 due to vesting of restricted share units, and disposals of 1,678 shares at $196.81 and 32,931 shares at $195.99.

How many STX shares does Mosley beneficially own after these transactions?

Following the reported transactions, Mosley beneficially owned 538,599 ordinary shares.

Why did 65,170 performance-based restricted share units vest on 09/14/2025?

The filing states the Compensation Committee determined the performance conditions were met for 65,170 of the 75,045 Performance Share Units granted on 09/09/2022, causing those shares to vest on 09/14/2025.

Were any derivative securities reported on the Form 4?

Yes. The Form 4 lists Restricted Share Units and Performance-Based Restricted Share Units as derivative securities that converted into ordinary shares upon vesting, with underlying amounts matching the reported acquisitions.

Who signed the Form 4 and when was it filed?

The Form 4 was signed by Louis J. Thorson as Attorney-in-Fact for William D. Mosley on 09/15/2025 as shown in the filing.