William D. Mosley - 14 Sep 2026 Form 4 Insider Report for Seagate Technology Holdings plc (STX)

Reporting relationship: CEO, Director
Issuer ticker: STX
Reported as of: 14 Sep 2026
Net transaction value: -$75,584,519
SEC form: 4
Accepted by SEC: 16 Sep 2026, 16:10:22 UTC
Prior SEC filing: 15 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 16 Sep 2026.

Key facts

This page summarizes William D. Mosley's Form 4 filing for Seagate Technology Holdings plc (STX).
3 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 16 Sep 2026, 16:10.

Change

Previous filing in this sequence was filed on 15 Sep 2026.
Current net transaction value: -$75,584,519.

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: 16 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: +177,000
Change %: +59%
Price: $0.000000^*
Shares after: 475,998
Date: 14 Sep 2026
Ownership: Direct
Footnotes: F1

STX transaction

Ordinary Shares

Sale

Transaction value: $75,584,519
Shares: -97,889
Change %: -21%
Price: $772.14
Shares after: 378,108
Date: 15 Sep 2026
Ownership: Direct
Footnotes: F2

Reported derivative securities

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

STX transaction Derivative

Performance-Based Restricted Share Units

Options Exercise

Transaction value
Shares: -177,000
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 14 Sep 2026
Ownership: Direct
Underlying class: Ordinary Shares
Underlying amount: 177,000
Exercise price: $0.000000
Footnotes: F3

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

Represents Ordinary Shares issued upon the vesting and settlement of Performance Share Units granted on September 11, 2023, following certification by the Compensation and People Committee of the achievement of the applicable performance conditions.

Footnote F2

Represents sales made pursuant to Issuer mandated sell-to-cover solely to satisfy tax withholding obligations.

Footnote F3

Performance Share Units granted on September 11, 2023 vested and were settled in Ordinary Shares upon certification of the applicable performance conditions by the Compensation and People Committee.