As of June 02, 2026, the three largest insider holders of STX are Holdings, L.P. Valueact (Director, 13.44Mn shares), William D Mosley (Ceo, 355.59K shares), Stephen J Luczo (Executive Chairman Cob, 225.94K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Judy Bruner | - | 0 | 14,314 | 21 Oct, 2025 |
| Robert A Bruggeworth | - | 6,591 | 0 | 22 Oct, 2024 |
| Michael R Cannon | - | 13,439 | 0 | 21 Oct, 2025 |
| Katherine Schuelke | Svp, Clo Corporate Secretary | 29,063 | 0 | 12 Dec, 2023 |
| Richard L Clemmer | - | 29,704 | 0 | 21 Oct, 2025 |
| Stephen J Luczo | Executive Chairman Cob | 0 | 225,941 | 08 Mar, 2022 |
| Edward J Zander | - | 0 | 41,357 | 22 Oct, 2021 |
| Thomas A Szlosek | - | 357 | 0 | 12 Nov, 2025 |
| Mark Adams | - | 0 | 12,285 | 13 Dec, 2021 |
| William D Mosley | Ceo | 355,591 | 0 | 02 Apr, 2026 |
| Holdings, L.P. Valueact | - | 0 | 13,437,070 | 22 Feb, 2022 |
| Jay L Geldmacher | - | 223 | 0 | 02 Feb, 2026 |
| Prat Bhatt | - | 13,869 | 0 | 21 Oct, 2025 |
| Dylan G. Haggart | - | 14,515 | 0 | 21 Oct, 2025 |
| Jeffrey D. Nygaard | Evp, Operations And Technology | 30,360 | 0 | 02 Feb, 2023 |
| Gianluca Romano | Evp Cfo | 65,335 | 0 | 12 Mar, 2026 |
| James Ci Lee | Evp Clo | 257 | 0 | 28 Jan, 2026 |
| Ban Seng Teh | Evp Chief Commercial Officer | 11,248 | 0 | 12 Mar, 2026 |
| Jeffrey D. Fochtman | Svp, Business Marketing | 14,736 | 0 | 14 Sep, 2022 |
| Ravi Naik | Evp, Lyve Storage Services | 38,857 | 0 | 23 Mar, 2023 |
| Shankar Arumugavelu | - | 7,626 | 0 | 12 Nov, 2025 |
| Yolanda Lee Conyers | - | 4,851 | 0 | 03 Mar, 2026 |
| Kian Fatt Chong | Evp Global Operations | 1,259 | 0 | 12 Mar, 2026 |
| John Christopher Morris | Evp Cto | 17,580 | 0 | 16 Mar, 2026 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 100 | $399.05 | 375,491 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 200 | $400.34 | 375,291 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 100 | $404.06 | 375,191 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 100 | $407.48 | 375,091 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 200 | $409.18 | 374,891 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 100 | $410.83 | 374,791 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 300 | $412.28 | 374,491 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 300 | $413.97 | 374,191 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 800 | $415.23 | 373,391 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 1,100 | $416.56 | 372,291 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 808 | $417.45 | 371,483 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 1,092 | $418.79 | 370,391 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 1,500 | $419.94 | 368,891 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 2,900 | $420.77 | 365,991 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 2,887 | $421.84 | 363,104 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 2,444 | $422.93 | 360,660 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 1,469 | $423.98 | 359,191 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 1,500 | $424.92 | 357,691 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 1,000 | $425.94 | 356,691 | D | S |
| 01 Apr, 2026 | William D Mosley | Ordinary Shares | D | 800 | $426.93 | 355,891 | D | S |