12 insiders reported 116 Form 4 transactions for Amphastar Pharmaceuticals, Inc. (AMPH) over the past 18 months (most recent 2026-06-03). Recent activity: ZASLOFF MICHAEL A (Director) Buy 8,143 shares, PRINS RICHARD K (Director) Sell 1,500 shares, Lee Howard (Director) Buy 8,143 shares, Gerst Diane G. (Director) Buy 8,143 shares, Deflin Gayle (Director) Buy 8,143 shares. Source: SEC Form 4.
| Date | Insider | Title | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-06-03 | ZASLOFF MICHAEL A | Director | Buy | 8,143 | $0 |
| 2026-06-03 | PRINS RICHARD K | Director | Sell | 1,500 | $0 |
| 2026-06-03 | Lee Howard | Director | Buy | 8,143 | $0 |
| 2026-06-03 | Gerst Diane G. | Director | Buy | 8,143 | $0 |
| 2026-06-03 | Deflin Gayle | Director | Buy | 8,143 | $0 |
| 2026-06-03 | Gaugh David Russell | Director | Buy | 8,143 | $0 |
| 2026-06-03 | PRINS RICHARD K | Director | Buy | 8,143 | $0 |
| 2026-06-03 | Lee Howard | Director | Sell | 769 | $14,188 |
| 2026-03-17 | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Sell | 9,784 | $177,873 |
| 2026-03-17 | Luo Mary Z. | COO, Chief Scientist, Chairman | Sell | 9,784 | $177,873 |
| 2026-03-17 | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Sell | 2,908 | $52,867 |
| 2026-03-17 | Luo Mary Z. | COO, Chief Scientist, Chairman | Sell | 2,908 | $52,867 |
| 2026-03-17 | Liawatidewi Yakob | EVP CORP ADMIN CENTER | Sell | 1,033 | $18,780 |
| 2026-03-17 | Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Sell | 1,225 | $22,270 |
| 2026-03-17 | PETERS WILLIAM J | CFO, EVP & TREASURER | Sell | 1,973 | $35,869 |
| 2026-03-11 | Luo Mary Z. | COO, Chief Scientist, Chairman | Buy | 180,504 | $0 |
| 2026-03-11 | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Buy | 180,504 | $0 |
| 2026-03-11 | Luo Mary Z. | COO, Chief Scientist, Chairman | Sell | 14,785 | $279,584 |
| 2026-03-11 | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Sell | 14,785 | $279,584 |
| 2026-03-11 | Luo Mary Z. | COO, Chief Scientist, Chairman | Buy | 72,462 | $0 |
| 2026-03-11 | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Buy | 72,462 | $0 |
| 2026-03-11 | Luo Mary Z. | COO, Chief Scientist, Chairman | Sell | 4,395 | $83,109 |
| 2026-03-11 | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Sell | 4,395 | $83,109 |
| 2026-03-11 | Liawatidewi Yakob | EVP CORP ADMIN CENTER | Buy | 35,450 | $0 |
| 2026-03-11 | Liawatidewi Yakob | EVP CORP ADMIN CENTER | Sell | 1,870 | $35,362 |
Source: SEC Form 4 filings · as of 2026-06-03