William D. Mosley - 09 Sep 2026 Form 4 Insider Report for Seagate Technology Holdings plc (STX)

Reporting relationship: CEO, Director
Issuer ticker: STX
Reported as of: 09 Sep 2026
Net transaction value: -$2,456,436
SEC form: 4
Accepted by SEC: 11 Sep 2026, 16:46:47 UTC
Prior SEC filing: 03 Sep 2026
Source filing: View source filing
Reporting owner signature: /s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley

Key filing fact

William D. Mosley filed Form 4 for Seagate Technology Holdings plc (STX) on 11 Sep 2026.

Key facts

This page summarizes William D. Mosley's Form 4 filing for Seagate Technology Holdings plc (STX).
6 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 11 Sep 2026, 16:46.

Change

Previous filing in this sequence was filed on 03 Sep 2026.
Current net transaction value: -$2,456,436.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001388390 Primary reporting owner

MOSLEY WILLIAM D

Relationship: CEO, Director
Address: SEAGATE TECHNOLOGY HOLDINGS PLC, 47488 KATO ROAD, FREMONT
Signature: /s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley
Signature date: 11 Sep 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

STX transaction

Ordinary Shares

Options Exercise

Transaction value
Shares: +2,815
Change %: +0.95%
Price: $0.000000^*
Shares after: 297,982
Date: 09 Sep 2026
Ownership: Direct

STX transaction

Ordinary Shares

Sale

Transaction value: $1,322,082
Shares: -1,534
Change %: -0.51%
Price: $862.13
Shares after: 296,449
Date: 10 Sep 2026
Ownership: Direct

STX transaction

Ordinary Shares

Options Exercise

Transaction value
Shares: +2,415
Change %: +0.81%
Price: $0.000000^*
Shares after: 298,864
Date: 09 Sep 2026
Ownership: Direct

STX transaction

Ordinary Shares

Sale

Transaction value: $1,134,354
Shares: -1,316
Change %: -0.44%
Price: $862.14
Shares after: 297,548
Date: 10 Sep 2026
Ownership: Direct

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

STX transaction Derivative

Restricted Share Unit

Options Exercise

Transaction value
Shares: -2,815
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 09 Sep 2026
Ownership: Direct
Underlying class: Ordinary Shares
Underlying amount: 2,815
Exercise price: $0.000000
Footnotes: F1

STX transaction Derivative

Restricted Share Unit

Options Exercise

Transaction value
Shares: -2,415
Change %: -11%
Price: $0.000000^*
Shares after: 19,328
Date: 09 Sep 2026
Ownership: Direct
Underlying class: Ordinary Shares
Underlying amount: 2,415
Exercise price: $0.000000
Footnotes: F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote 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"). One-quarter of the shares vested on September 9, 2023 and the remaining portion vested in equal quarterly installments over the following three years for a total vesting period of four years.

Footnote F2

Consists of a grant of RSUs awarded to the Reporting Person under the Plan. 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.