WILLIAM D. MOSLEY - 09 Dec 2025 Form 4 Insider Report for Seagate Technology Holdings plc (STX)

Role: CEO, Director
Signature: /s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley
Issuer symbol: STX
Transactions as of: 09 Dec 2025
Net transactions value: -$747,882
Form type: 4
Filing time: 11 Dec 2025, 16:04:36 UTC
Previous filing: 02 Dec 2025
Next filing: 12 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
MOSLEY WILLIAM D	CEO, Director	SEAGATE TECHNOLOGY HOLDINGS PLC, 47488 KATO ROAD, FREMONT	/s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley	11 Dec 2025	0001388390

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership
transaction	STX	Ordinary Shares	Options Exercise	$0	+2,815	+0.63%	$0.000000	448,483	09 Dec 2025	Direct
transaction	STX	Ordinary Shares	Tax liability	$402,510	-1,423	-0.32%	$282.86	447,060	09 Dec 2025	Direct
transaction	STX	Ordinary Shares	Options Exercise	$0	+2,415	+0.54%	$0.000000	449,475	09 Dec 2025	Direct
transaction	STX	Ordinary Shares	Tax liability	$345,372	-1,221	-0.27%	$282.86	448,254	09 Dec 2025	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	STX	Restricted Share Unit	Options Exercise	$0	-2,815	-25%	$0.000000	8,445	09 Dec 2025	Ordinary Shares	2,815	$0.000000	Direct	F1
transaction	STX	Restricted Share Unit	Options Exercise	$0	-2,415	-8.3%	$0.000000	26,573	09 Dec 2025	Ordinary Shares	2,415	$0.000000	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Consists of a grant of RSUs awarded to the Reporting Person under the Seagate Technology Holdings plc 2022 Equity Incentive Plan (the "2022 Plan"). Subject to the Reporting Person's continuous employment, such RSUs vested as to one-quarter of the shares on September 9, 2023 and the remaining portion shall vest in equal quarterly installments over the following three years for a total vesting period of four years.
F2	Consists of a grant of RSUs awarded to the Reporting Person under the 2022 Plan. Subject to the Reporting Person's continuous employment one-quarter vested on September 9, 2025 and the remaining portion shall vest in equal quarterly installments over the following three years for a total vesting period of four years.

Content

Consists of a grant of RSUs awarded to the Reporting Person under the Seagate Technology Holdings plc 2022 Equity Incentive Plan (the "2022 Plan"). Subject to the Reporting Person's continuous employment, such RSUs vested as to one-quarter of the shares on September 9, 2023 and the remaining portion shall vest in equal quarterly installments over the following three years for a total vesting period of four years.

Consists of a grant of RSUs awarded to the Reporting Person under the 2022 Plan. Subject to the Reporting Person's continuous employment one-quarter vested on September 9, 2025 and the remaining portion shall vest in equal quarterly installments over the following three years for a total vesting period of four years.