AMTM (Amentum Holdings, Inc.)
Insider Trading Activity
Every open-market purchase and sale reported by AMTM officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-05-07 | Stephen A Arnette | Chief Operating Officer | MIXED | — | — |
| 2026-05-07 | Jill L Bruning | Chief Technology Officer | MIXED | — | — |
| 2026-05-07 | Travis Barton Johnson | Chief Financial Officer | MIXED | — | — |
| 2026-05-07 | Sean Thomas Mullen | Chief Growth Officer | MIXED | — | — |
| 2026-05-07 | John E. Heller | Chief Executive Officer | MIXED | — | — |
| 2026-03-05 | Jill L Bruning | Chief Technology Officer | G | — | — |
| 2026-03-04 | Stephen A Arnette | Chief Operating Officer | MIXED | — | — |
| 2026-02-18 | Michele T St. Mary | Chief Legal Officer & GC | MIXED | — | — |
| 2026-02-10 | STEVEN J. DEMETRIOU | Executive Chair | — | — | — |
| 2026-02-10 | John C. Vollmer | Director | MIXED | — | — |
| 2026-02-10 | Christopher M.T. Thompson | Director | A | — | — |
| 2026-02-10 | Barbara Loughran | Director | A | — | — |
| 2026-02-10 | RALPH E EBERHART | Director | MIXED | — | — |
| 2026-02-10 | Vincent K Brooks | Director | MIXED | — | — |
| 2026-02-10 | Sandra E. Rowland | Director | MIXED | — | — |
| 2026-02-10 | SUSAN LESLIE IRELAND | Director | A | — | — |
| 2026-01-29 | John E. Heller | Chief Executive Officer | MIXED | — | — |
| 2025-12-19 | John E. Heller | Chief Executive Officer | — | — | — |
| 2025-12-19 | Stephen A Arnette | Chief Operating Officer | — | — | — |
| 2025-12-19 | Jill L Bruning | Chief Technology Officer | — | — | — |
| 2025-12-19 | Sean Thomas Mullen | Chief Growth Officer | MIXED | — | — |
| 2025-12-09 | Darren Burton | Chief People Officer | MIXED | — | — |
| 2025-11-19 | STEVEN J. DEMETRIOU | Executive Chair | MIXED | — | — |
| 2025-11-19 | Stephen A Arnette | Chief Operating Officer | MIXED | — | — |
| 2025-11-19 | Michele T St. Mary | Chief Legal Officer & GC | A | — | — |
| 2025-11-19 | Travis Barton Johnson | Chief Financial Officer | A | — | — |
| 2025-11-19 | Darren Burton | Chief People Officer | A | — | — |
| 2025-11-19 | Jill L Bruning | Chief Technology Officer | A | — | — |
| 2025-11-19 | John E. Heller | Chief Executive Officer | A | — | — |
| 2025-11-19 | Sean Thomas Mullen | Chief Growth Officer | A | — | — |
| 2025-11-18 | Stephen A Arnette | Chief Operating Officer | MIXED | — | — |
| 2025-11-10 | Stephen A Arnette | Chief Operating Officer | MIXED | — | — |
| 2025-11-10 | STEVEN J. DEMETRIOU | Executive Chair | MIXED | — | — |
| 2025-11-10 | Sean Thomas Mullen | Chief Growth Officer | MIXED | — | — |
| 2025-11-10 | John E. Heller | Chief Executive Officer | MIXED | — | — |
| 2025-11-10 | Jill L Bruning | Chief Technology Officer | MIXED | — | — |
| 2025-11-10 | Travis Barton Johnson | Chief Financial Officer | MIXED | — | — |
| 2025-05-12 | Amentum Joint Venture LP | Director | J | — | — |
| 2025-05-12 | LG GP Holding IV LLC | 10%+ Owner | J | — | — |
| 2025-05-12 | ALAN E GOLDBERG | Director | J | — | — |
| 2025-05-12 | Lindsay Goldberg Employee Co-Inv. IV L.P. | 10%+ Owner | J | — | — |
| 2025-04-10 | Christopher M.T. Thompson | Director | A | — | — |
| 2025-04-10 | Sandra E. Rowland | Director | A | — | — |
| 2025-04-10 | SUSAN LESLIE IRELAND | Director | A | — | — |
| 2025-04-10 | Barbara Loughran | Director | A | — | — |
| 2025-04-10 | RALPH E EBERHART | Director | A | — | — |
| 2025-04-10 | Vincent K Brooks | Director | A | — | — |
| 2025-04-10 | John C. Vollmer | Director | A | — | — |
| 2025-04-08 | Amentum Joint Venture GP LLC | Director | A | — | — |
| 2025-03-19 | Michele T St. Mary | Chief Legal Officer & GC | A | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | Director | 45,026,743 | — |
| — | 10%+ Owner | 45,026,743 | — |
| — | 10%+ Owner | 45,026,743 | — |
| — | Director | 2,433,022 | — |
| — | Executive Chair | 861,218 | — |
| — | Director | 424,780 | — |
| — | Chief Executive Officer | 384,203 | — |
| — | Chief Technology Officer | 200,188 | — |
| — | Chief Financial Officer | 118,187 | — |
| — | Chief Operating Officer | 109,966 | — |
| — | Director | 48,120 | — |
| — | Chief Growth Officer | 35,210 | — |
| — | Director | 27,462 | — |
| — | Chief Legal Officer & GC | 27,043 | — |
| — | Chief People Officer | 23,600 | — |
| — | Director | 15,062 | — |
| — | Director | 15,011 | — |
| — | Director | 9,662 | — |
| — | Director | 8,509 | — |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the AMTM quote page; the site-wide leaderboard is on the insider transactions hub.