Key facts
- This page summarizes William D. Mosley's Form 4 filing for Seagate Technology Holdings plc (STX).
- 13 reported transactions and 7 derivative rows are listed below.
- Accepted by SEC: 24 Aug 2026, 17:10.
William D. Mosley - 20 Aug 2026 Form 4 Insider Report for Seagate Technology Holdings plc (STX)
- Reporting relationship
- CEO, Director
- Issuer ticker
- STX
- Reported as of
- 20 Aug 2026
- Net transaction value
- -$15,406,022
- SEC form
- 4
- Accepted by SEC
- 24 Aug 2026, 17:10:53 UTC
- Prior SEC filing
- 04 Aug 2026
- Next SEC filing
- 03 Sep 2026
- Source filing
- View source filing
- Reporting owner signature
- /s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley
Source evidence
Original filing metadata and source links for verification.
5 source fields
Reporting owner
1 detail
Key filing fact
William D. Mosley filed Form 4 for Seagate Technology Holdings plc (STX) on 24 Aug 2026.
Change
- Previous filing in this sequence was filed on 04 Aug 2026.
- Current net transaction value: -$15,406,022.
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
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
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
- 24 Aug 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
- +6,404
- Change %
- +2.2%
- Price
- $0.000000*
- Shares after
- 301,921
- Date
- 20 Aug 2026
- Ownership
- Direct
STX
transaction
Ordinary Shares
Sale
- Transaction value
- $2,919,869
- Shares
- -3,438
- Change %
- -1.1%
- Price
- $849.35
- Shares after
- 298,483
- Date
- 21 Aug 2026
- Ownership
- Direct
STX
transaction
Ordinary Shares
Options Exercise
- Transaction value
- Shares
- +21,065
- Change %
- +7.1%
- Price
- $0.000000*
- Shares after
- 319,548
- Date
- 20 Aug 2026
- Ownership
- Direct
STX
transaction
Ordinary Shares
Sale
- Transaction value
- $9,604,504
- Shares
- -11,308
- Change %
- -3.5%
- Price
- $849.35
- Shares after
- 308,240
- Date
- 21 Aug 2026
- Ownership
- Direct
STX
transaction
Ordinary Shares
Options Exercise
- Transaction value
- Shares
- +6,320
- Change %
- +2.1%
- Price
- $0.000000*
- Shares after
- 314,560
- Date
- 20 Aug 2026
- Ownership
- Direct
STX
transaction
Ordinary Shares
Sale
- Transaction value
- $2,881,648
- Shares
- -3,393
- Change %
- -1.1%
- Price
- $849.35
- Shares after
- 311,168
- Date
- 21 Aug 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
- -6,404
- Change %
- -25%
- Price
- $0.000000*
- Shares after
- 19,213
- Date
- 20 Aug 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 6,404
- Exercise price
- $0.000000
- Footnotes
- F1
STX
transaction
Derivative
Restricted Share Unit
Options Exercise
- Transaction value
- Shares
- -6,320
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Aug 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 6,320
- Exercise price
- $0.000000
- Footnotes
- F2
STX
transaction
Derivative
Restricted Share Unit
Options Exercise
- Transaction value
- Shares
- -21,065
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Aug 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 21,065
- Exercise price
- $0.000000
- Footnotes
- F2
STX
transaction
Derivative
Restricted Share Unit
Award
- Transaction value
- Shares
- +5,309
- Change %
- Price
- $0.000000*
- Shares after
- 5,309
- Date
- 20 Aug 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 5,309
- Exercise price
- $0.000000
- Footnotes
- F3
STX
transaction
Derivative
Restricted Share Unit
Award
- Transaction value
- Shares
- +5,280
- Change %
- Price
- $0.000000*
- Shares after
- 5,280
- Date
- 20 Aug 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 5,280
- Exercise price
- $0.000000
- Footnotes
- F4
STX
transaction
Derivative
Restricted Share Unit
Award
- Transaction value
- Shares
- +1,584
- Change %
- Price
- $0.000000*
- Shares after
- 1,584
- Date
- 20 Aug 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 1,584
- Exercise price
- $0.000000
- Footnotes
- F4
STX
transaction
Derivative
NQ Stock Option
Award
- Transaction value
- Shares
- +31,856
- Change %
- Price
- $0.000000*
- Shares after
- 31,856
- Date
- 20 Aug 2026
- Ownership
- Direct
- Underlying class
- Ordinary Shares
- Underlying amount
- 31,856
- Exercise price
- $850.24
- Footnotes
- F5
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 5 footnotes
Footnote F1
Consists of a grant of Restricted Share Unit (RSU) awarded to the Reporting Person under the Seagate Technology Holdings plc 2022 Equity Incentive Plan (the "2022 Plan") subject to a four-year vesting schedule. Subject to the Reporting Person's continuous employment, such RSUs vest as to one-quarter of the shares on August 20, 2026 and then in equal quarterly installments thereafter.
Footnote F2
Consists of a grant of RSUs awarded to the Reporting Person under the Plan. 100% of such RSUs vested on the first anniversary of the grant date, August 20, 2026.
Footnote F3
Consists of a grant of RSUs awarded to the Reporting Person under the Plan subject to a four-year vesting schedule. Subject to the Reporting Person's continuous employment, such RSUs vest as to one-quarter of the shares on August 20, 2027 and then in equal quarterly installments thereafter.
Footnote F4
Consists of a grant of RSUs awarded to the Reporting Person under the Plan. Subject to the Reporting Person's continuous employment, 100% of such RSUs will vest on the first anniversary of the grant date, August 20, 2027.
Footnote F5
Consists of Options awarded to the Reporting Person under the Plan subject to a four-year vesting schedule. Subject to the Reporting Person's continuous employment, such Options vest as to one-quarter of the shares on August 20, 2027 and the remaining portion shall vest in equal monthly installments over the following three years for a total vesting period of four years.