SEC Form 4 · accession 0001137789-26-000163
Seagate Technology Holdings plc · STX
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
William D Mosley
Officer — CEO · Director
Period of report
Aug 3, 2026
Accepted (ET)
Aug 4, 2026 · 6:09 pm EDT
Rule 10b5-1 plan
yes — trade under a plan
Issuer CIK
0001137789
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Ordinary SharesF1 | Aug 3, 2026 | M | 14,000 | $46.23 | A | 325,517 | D | |
| Ordinary SharesF2 | Aug 3, 2026 | S | 80 | $783.835 | D | 325,437 | D | |
| Ordinary Shares | Aug 3, 2026 | S | 40 | $786.12 | D | 325,397 | D | |
| Ordinary SharesF3 | Aug 3, 2026 | S | 160 | $787.7675 | D | 325,237 | D | |
| Ordinary SharesF4 | Aug 3, 2026 | S | 120 | $789.5467 | D | 325,117 | D | |
| Ordinary SharesF5 | Aug 3, 2026 | S | 440 | $790.9827 | D | 324,677 | D | |
| Ordinary SharesF6 | Aug 3, 2026 | S | 711 | $792.7229 | D | 323,966 | D | |
| Ordinary SharesF7 | Aug 3, 2026 | S | 480 | $793.7025 | D | 323,486 | D | |
| Ordinary SharesF8 | Aug 3, 2026 | S | 368 | $794.3873 | D | 323,118 | D | |
| Ordinary SharesF9 | Aug 3, 2026 | S | 761 | $795.8147 | D | 322,357 | D | |
| Ordinary SharesF10 | Aug 3, 2026 | S | 680 | $797.0435 | D | 321,677 | D | |
| Ordinary SharesF11 | Aug 3, 2026 | S | 560 | $797.8479 | D | 321,117 | D | |
| Ordinary SharesF12 | Aug 3, 2026 | S | 480 | $799.2675 | D | 320,637 | D | |
| Ordinary SharesF13 | Aug 3, 2026 | S | 520 | $800.0785 | D | 320,117 | D | |
| Ordinary SharesF14 | Aug 3, 2026 | S | 400 | $801.045 | D | 319,717 | D | |
| Ordinary SharesF15 | Aug 3, 2026 | S | 360 | $802.0833 | D | 319,357 | D | |
| Ordinary SharesF16 | Aug 3, 2026 | S | 520 | $803.7285 | D | 318,837 | D | |
| Ordinary SharesF17 | Aug 3, 2026 | S | 840 | $804.7324 | D | 317,997 | D | |
| Ordinary SharesF18 | Aug 3, 2026 | S | 640 | $806.4669 | D | 317,357 | D | |
| Ordinary SharesF19 | Aug 3, 2026 | S | 280 | $807.6486 | D | 317,077 | D | |
| Ordinary SharesF20 | Aug 3, 2026 | S | 697 | $808.7248 | D | 316,380 | D | |
| Ordinary SharesF21 | Aug 3, 2026 | S | 383 | $809.7094 | D | 315,997 | D | |
| Ordinary SharesF22 | Aug 3, 2026 | S | 520 | $810.4362 | D | 315,477 | D | |
| Ordinary SharesF23 | Aug 3, 2026 | S | 640 | $811.8179 | D | 314,837 | D | |
| Ordinary SharesF24 | Aug 3, 2026 | S | 400 | $812.836 | D | 314,437 | D | |
| Ordinary SharesF25 | Aug 3, 2026 | S | 366 | $814.0744 | D | 314,071 | D | |
| Ordinary SharesF26 | Aug 3, 2026 | S | 394 | $814.9919 | D | 313,677 | D | |
| Ordinary SharesF27 | Aug 3, 2026 | S | 320 | $815.8725 | D | 313,357 | D | |
| Ordinary SharesF28 | Aug 3, 2026 | S | 440 | $817.1682 | D | 312,917 | D | |
| Ordinary SharesF29 | Aug 3, 2026 | S | 320 | $818.315 | D | 312,597 | D |
Table II — derivative securities
| Security | Conv. / exercise price | Date | Code | Shares | A/D | Exercisable | Expires | Underlying | Underlying shares | Owned after | D/I |
|---|---|---|---|---|---|---|---|---|---|---|---|
| NQ OptionsF30 | $46.23 | Aug 3, 2026 | M | 14,000 | D | — | Sep 9, 2027 | Ordinary Shares | 14,000 | 111,100 | D |
Explanation of responses
- F1All 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.
- F10These Ordinary Shares were sold in multiple trades at prices ranging from $796.39 to $797.35. 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.
- F11These Ordinary Shares were sold in multiple trades at prices ranging from $797.41 to $798.36. 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.
- F12These Ordinary Shares were sold in multiple trades at prices ranging from $798.60 to $799.58. 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.
- F13These Ordinary Shares were sold in multiple trades at prices ranging from $799.64 to $800.58. 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.
- F14These Ordinary Shares were sold in multiple trades at prices ranging from $800.70 to $801.31. 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.
- F15These Ordinary Shares were sold in multiple trades at prices ranging from $801.71 to $802.65. 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.
- F16These Ordinary Shares were sold in multiple trades at prices ranging from $803.19 to $804.17. 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.
- F17These Ordinary Shares were sold in multiple trades at prices ranging from $804.38 to $805.19. 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.
- F18These Ordinary Shares were sold in multiple trades at prices ranging from $806.12 to $807.01. 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.
- F19These Ordinary Shares were sold in multiple trades at prices ranging from $807.14 to $807.99. 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.
- F2These Ordinary Shares were sold in multiple trades at prices ranging from $783.83 to $783.84. 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.
- F20These Ordinary Shares were sold in multiple trades at prices ranging from $808.18 to $809.09. 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.
- F21These Ordinary Shares were sold in multiple trades at prices ranging from $809.20 to $810.08. 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.
- F22These Ordinary Shares were sold in multiple trades at prices ranging from $810.20 to $811.08. 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.
- F23These Ordinary Shares were sold in multiple trades at prices ranging from $811.38 to $812.36. 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.
- F24These Ordinary Shares were sold in multiple trades at prices ranging from $812.39 to $813.20. 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.
- F25These Ordinary Shares were sold in multiple trades at prices ranging from $813.42 to $814.40. 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.
- F26These Ordinary Shares were sold in multiple trades at prices ranging from $814.43 to $815.31. 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.
- F27These Ordinary Shares were sold in multiple trades at prices ranging from $815.65 to $816.17. 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.
- F28These Ordinary Shares were sold in multiple trades at prices ranging from $816.65 to $817.59. 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.
- F29These Ordinary Shares were sold in multiple trades at prices ranging from $817.74 to $818.58. 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.
- F3These Ordinary Shares were sold in multiple trades at prices ranging from $787.71 to $787.79. 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.
- F30Options granted to the Reporting Person under the Issuer's 2012 Equity Incentive Plan are subject to a four year vesting schedule. Subject to continuous employment, one quarter of the option shares vested on September 9, 2021. The remaining option shares vest in equal monthly installments over the 36 months following September 9, 2021.
- F4These Ordinary Shares were sold in multiple trades at prices ranging from $789.02 to $789.84. 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.
- F5These Ordinary Shares were sold in multiple trades at prices ranging from $790.50 to $791.22. 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.
- F6These Ordinary Shares were sold in multiple trades at prices ranging from $792.17 to $793.13. 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.
- F7These Ordinary Shares were sold in multiple trades at prices ranging from $793.19 to $794.18. 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.
- F8These Ordinary Shares were sold in multiple trades at prices ranging from $794.22 to $795.04. 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.
- F9These Ordinary Shares were sold in multiple trades at prices ranging from $795.32 to $796.19. 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.