William D. Mosley - 09 Sep 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 Sep 2025
Net transactions value: -$2,520,941
Form type: 4
Filing time: 11 Sep 2025, 16:05:24 UTC
Previous filing: 04 Sep 2025
Next filing: 15 Sep 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 Sep 2025	0001388390

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	STX	Ordinary Shares	Options Exercise	$0	+9,007	+2%	$0.000000	467,919	09 Sep 2025	Direct
transaction	STX	Ordinary Shares	Tax liability	$872,118	-4,552	-0.97%	$191.59	463,367	09 Sep 2025	Direct
transaction	STX	Ordinary Shares	Options Exercise	$0	+2,815	+0.61%	$0.000000	466,182	09 Sep 2025	Direct
transaction	STX	Ordinary Shares	Tax liability	$272,633	-1,423	-0.31%	$191.59	464,759	09 Sep 2025	Direct
transaction	STX	Ordinary Shares	Options Exercise	$0	+9,662	+2.1%	$0.000000	474,421	09 Sep 2025	Direct
transaction	STX	Ordinary Shares	Tax liability	$935,534	-4,883	-1%	$191.59	469,538	09 Sep 2025	Direct
transaction	STX	Ordinary Shares	Options Exercise	$0	+4,550	+0.97%	$0.000000	474,088	09 Sep 2025	Direct
transaction	STX	Ordinary Shares	Tax liability	$440,657	-2,300	-0.49%	$191.59	471,788	09 Sep 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	-9,007	-100%	$0.000000	0	09 Sep 2025	Ordinary Shares	9,007	$0.000000	Direct	F1
transaction	STX	Restricted Share Unit	Options Exercise	$0	-2,815	-20%	$0.000000	11,260	09 Sep 2025	Ordinary Shares	2,815	$0.000000	Direct	F2
transaction	STX	Restricted Share Unit	Options Exercise	$0	-9,662	-25%	$0.000000	28,988	09 Sep 2025	Ordinary Shares	9,662	$0.000000	Direct	F3
transaction	STX	Restricted Share Unit	Options Exercise	$0	-4,550	-100%	$0.000000	0	09 Sep 2025	Ordinary Shares	4,550	$0.000000	Direct	F4

* 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 plc Equity Incentive Plan (the "Plan"). Subject to the Reporting Person's continuous employment, one-quarter of the shares vested on September 9, 2022 and each one year anniversary thereafter for a total vesting period of four years.
F2	Consists of a grant of RSUs awarded to the Reporting Person under the Plan. Subject to the Reporting Person's continuous employment, one-quarter of the shares vested 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.
F3	Consists of a grant of RSUs awarded to the Reporting Person under the Plan. Subject to the Reporting Person's continuous employment, one-quarter of the shares 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.
F4	Consists of a grant of RSUs awarded to the Reporting Person under the Plan. Such RSUs vested 100% on September 9, 2025, the first anniversary of the grant.