=== SEC Form 4 — Statement of Changes in Beneficial Ownership ===
Document Type: 4
Period of Report: 2026-10-01
10b5-1 Pre-arranged Plan: Yes
--- Issuer ---
Name: Seagate Technology Holdings plc (STX)
CIK: 0001137789
--- Reporting Owner ---
Name: MOSLEY WILLIAM D
CIK: 0001388390
Role: Director, Officer (CEO)
--- Non-Derivative Transactions ---
[Transaction #1]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -360 | Price: $929.01
Total Value: $334,443.20
Shares Owned After: 372,750.25 | Ownership: D (Direct)
Footnotes:
[F1] All transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 18, 2026.
[F2] These Ordinary Shares were sold in multiple trades at prices ranging from $928.44 to $929.30. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #2]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -855 | Price: $930.03
Total Value: $795,178.56
Shares Owned After: 371,895.25 | Ownership: D (Direct)
Footnotes:
[F3] These Ordinary Shares were sold in multiple trades at prices ranging from $929.51 to $930.50. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #3]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -1,665 | Price: $930.99
Total Value: $1,550,105.01
Shares Owned After: 370,230.25 | Ownership: D (Direct)
Footnotes:
[F4] These Ordinary Shares were sold in multiple trades at prices ranging from $930.53 to $931.48. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #4]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -1,320 | Price: $932.04
Total Value: $1,230,288.58
Shares Owned After: 368,910.25 | Ownership: D (Direct)
Footnotes:
[F5] These Ordinary Shares were sold in multiple trades at prices ranging from $931.56 to $932.55. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #5]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -840 | Price: $933.28
Total Value: $783,952.01
Shares Owned After: 368,070.25 | Ownership: D (Direct)
Footnotes:
[F6] These Ordinary Shares were sold in multiple trades at prices ranging from $932.73 to $933.67. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #6]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -822 | Price: $934.35
Total Value: $768,036.77
Shares Owned After: 367,248.25 | Ownership: D (Direct)
Footnotes:
[F7] These Ordinary Shares were sold in multiple trades at prices ranging from $933.77 to $934.76. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #7]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -640 | Price: $935.15
Total Value: $598,495.62
Shares Owned After: 366,608.25 | Ownership: D (Direct)
Footnotes:
[F8] These Ordinary Shares were sold in multiple trades at prices ranging from $934.83 to $935.70. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #8]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -759 | Price: $936.43
Total Value: $710,750.29
Shares Owned After: 365,849.25 | Ownership: D (Direct)
Footnotes:
[F9] These Ordinary Shares were sold in multiple trades at prices ranging from $935.84 to $936.80. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #9]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -579 | Price: $937.33
Total Value: $542,713.20
Shares Owned After: 365,270.25 | Ownership: D (Direct)
Footnotes:
[F10] These Ordinary Shares were sold in multiple trades at prices ranging from $936.88 to $937.83. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #10]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -640 | Price: $938.32
Total Value: $600,524.42
Shares Owned After: 364,630.25 | Ownership: D (Direct)
Footnotes:
[F11] These Ordinary Shares were sold in multiple trades at prices ranging from $937.91 to $938.67. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #11]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -720 | Price: $939.27
Total Value: $676,274.83
Shares Owned After: 363,910.25 | Ownership: D (Direct)
Footnotes:
[F12] These Ordinary Shares were sold in multiple trades at prices ranging from $938.92 to $939.89. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #12]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -80 | Price: $940.20
Total Value: $75,216.00
Shares Owned After: 363,830.25 | Ownership: D (Direct)
Footnotes:
[F13] These Ordinary Shares were sold in multiple trades at prices ranging from $940.19 to $940.21. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #13]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -40 | Price: $941.22
Total Value: $37,648.80
Shares Owned After: 363,790.25 | Ownership: D (Direct)
[Transaction #14]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -280 | Price: $943.21
Total Value: $264,099.61
Shares Owned After: 363,510.25 | Ownership: D (Direct)
Footnotes:
[F14] These Ordinary Shares were sold in multiple trades at prices ranging from $942.72 to $943.68. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #15]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -440 | Price: $944.81
Total Value: $415,714.82
Shares Owned After: 363,070.25 | Ownership: D (Direct)
Footnotes:
[F15] These Ordinary Shares were sold in multiple trades at prices ranging from $944.50 to $945.46. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
[Transaction #16]
Security: Ordinary Shares
Date: 2026-10-01 | Code: S (Open market sale)
Shares: -962 | Price: $945.97
Total Value: $910,022.76
Shares Owned After: 362,108.25 | Ownership: D (Direct)
Footnotes:
[F16] These Ordinary Shares were sold in multiple trades at prices ranging from $945.60 to $946.34. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
--- Footnotes (Complete Index) ---
F1: All transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 18, 2026.
F10: These Ordinary Shares were sold in multiple trades at prices ranging from $936.88 to $937.83. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F11: These Ordinary Shares were sold in multiple trades at prices ranging from $937.91 to $938.67. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F12: These Ordinary Shares were sold in multiple trades at prices ranging from $938.92 to $939.89. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F13: These Ordinary Shares were sold in multiple trades at prices ranging from $940.19 to $940.21. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F14: These Ordinary Shares were sold in multiple trades at prices ranging from $942.72 to $943.68. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F15: These Ordinary Shares were sold in multiple trades at prices ranging from $944.50 to $945.46. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F16: These Ordinary Shares were sold in multiple trades at prices ranging from $945.60 to $946.34. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F2: These Ordinary Shares were sold in multiple trades at prices ranging from $928.44 to $929.30. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F3: These Ordinary Shares were sold in multiple trades at prices ranging from $929.51 to $930.50. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F4: These Ordinary Shares were sold in multiple trades at prices ranging from $930.53 to $931.48. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F5: These Ordinary Shares were sold in multiple trades at prices ranging from $931.56 to $932.55. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F6: These Ordinary Shares were sold in multiple trades at prices ranging from $932.73 to $933.67. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F7: These Ordinary Shares were sold in multiple trades at prices ranging from $933.77 to $934.76. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F8: These Ordinary Shares were sold in multiple trades at prices ranging from $934.83 to $935.70. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
F9: These Ordinary Shares were sold in multiple trades at prices ranging from $935.84 to $936.80. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares and prices at which the transaction was effected.
--- Signature ---
/s/ /s/ Louis J. Thorson, Attorney-in-Fact for William D. Mosley (2026-10-02)
