AMPH (Amphastar Pharmaceuticals, Inc.)
Insider Trading Activity
Every open-market purchase and sale reported by AMPH 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 |
|---|---|---|---|---|---|
| 2026-09-03 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | Sell | — | — |
| 2026-08-12 | RICHARD K PRINS | Director | Sell | — | — |
| 2026-08-11 | WILLIAM J PETERS | CFO, EVP & TREASURER | MIXED | — | — |
| 2026-07-13 | Anthony T Pierce | Director | A | — | — |
| 2026-06-03 | MICHAEL A ZASLOFF | Director | A | — | — |
| 2026-06-03 | RICHARD K PRINS | Director | MIXED | — | — |
| 2026-06-03 | Howard Lee | Director | MIXED | — | — |
| 2026-06-03 | Gayle Deflin | Director | A | — | — |
| 2026-06-03 | David Russell Gaugh | Director | A | — | — |
| 2026-06-03 | Diane G. Gerst | Director | A | — | — |
| 2026-03-17 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | F | — | — |
| 2026-03-17 | Yakob Liawatidewi | EVP CORP ADMIN CENTER | F | — | — |
| 2026-03-17 | Jack Y. Zhang | CEO & CHIEF SCIENTIFIC OFFICER | F | — | — |
| 2026-03-17 | WILLIAM J PETERS | CFO, EVP & TREASURER | F | — | — |
| 2026-03-11 | Yakob Liawatidewi | EVP CORP ADMIN CENTER | MIXED | — | — |
| 2026-03-11 | WILLIAM J PETERS | CFO, EVP & TREASURER | MIXED | — | — |
| 2026-03-11 | Jack Y. Zhang | CEO & CHIEF SCIENTIFIC OFFICER | MIXED | — | — |
| 2026-03-11 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | MIXED | — | — |
| 2026-03-10 | WILLIAM J PETERS | CFO, EVP & TREASURER | F | — | — |
| 2026-03-10 | Yakob Liawatidewi | EVP CORP ADMIN CENTER | F | — | — |
| 2026-03-10 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | F | — | — |
| 2026-03-10 | Jack Y. Zhang | CEO & CHIEF SCIENTIFIC OFFICER | F | — | — |
| 2026-03-06 | WILLIAM J PETERS | CFO, EVP & TREASURER | F | — | — |
| 2026-03-06 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | F | — | — |
| 2026-03-06 | Yakob Liawatidewi | EVP CORP ADMIN CENTER | F | — | — |
| 2026-03-06 | Mary Z. Luo | COO, Chief Scientist, Chairman | F | — | — |
| 2025-12-18 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | MIXED | — | — |
| 2025-12-15 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-11-25 | RICHARD K PRINS | Director | MIXED | — | — |
| 2025-11-17 | Floyd F. Petersen | Director | MIXED | — | — |
| 2025-11-05 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-10-02 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-09-03 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-08-04 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-07-22 | David Russell Gaugh | Director | A | — | — |
| 2025-07-03 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-06-16 | Mary Z. Luo | COO, Chief Scientist, Chairman | M | — | — |
| 2025-06-04 | Diane G. Gerst | Director | A | — | — |
| 2025-06-04 | RICHARD K PRINS | Director | A | — | — |
| 2025-06-04 | Howard Lee | Director | MIXED | — | — |
| 2025-06-04 | Gayle Deflin | Director | A | — | — |
| 2025-06-04 | Floyd F. Petersen | Director | MIXED | — | — |
| 2025-06-04 | MICHAEL A ZASLOFF | Director | A | — | — |
| 2025-05-20 | WILLIAM J PETERS | CFO, EVP & TREASURER | F | — | — |
| 2025-05-02 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-04-02 | Floyd F. Petersen | Director | Sell | — | — |
| 2025-03-18 | WILLIAM J PETERS | CFO, EVP & TREASURER | F | — | — |
| 2025-03-18 | Yakob Liawatidewi | EVP CORP ADMIN CENTER | F | — | — |
| 2025-03-18 | Rong Zhou | SENIOR EVP, PRODUCTION CENTER | F | — | — |
| 2025-03-18 | Jack Y. Zhang | CEO & CHIEF SCIENTIFIC OFFICER | MIXED | — | — |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| — | COO, Chief Scientist, Chairman | 9,669,569 | — |
| — | CEO & CHIEF SCIENTIFIC OFFICER | 4,235,177 | — |
| — | 10%+ Owner | 3,696,949 | — |
| — | Director | 269,289 | — |
| — | CFO, EVP & TREASURER | 181,026 | — |
| — | President and General Counsel | 179,276 | — |
| — | SENIOR EVP, PRODUCTION CENTER | 174,203 | — |
| — | Director | 160,119 | — |
| — | EVP CORP ADMIN CENTER | 124,351 | — |
| — | Director | 89,263 | — |
| — | Director | 73,794 | — |
| — | Corp. Exec. VP of Operations | 59,307 | — |
| — | Director | 37,667 | — |
| — | Director | 31,899 | — |
| — | Director | 29,625 | — |
| — | Director | 19,170 | — |
| — | Director | 19,057 | — |
| — | Director | 14,447 | — |
| — | Director | 7,886 | — |
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 AMPH quote page; the site-wide leaderboard is on the insider transactions hub.