13 insiders reported 120 Form 4 transactions for Amphastar Pharmaceuticals, Inc. (AMPH) over the past 18 months (most recent 2026-08-12). Recent activity: PRINS RICHARD K (Director) Sell 7,973 shares, PETERS WILLIAM J (CFO, EVP & TREASURER) Buy 5,053 shares, PETERS WILLIAM J (CFO, EVP & TREASURER) Sell 8,180 shares, Pierce Anthony T (Director) Buy 7,886 shares, ZASLOFF MICHAEL A (Director) Buy 8,143 shares. Source: SEC Form 4.
| Date | Insider | Title | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-12 | PRINS RICHARD K | Director | Sell | 7,973 | $161,852 |
| 2026-08-11 | PETERS WILLIAM J | CFO, EVP & TREASURER | Buy | 5,053 | $99,999 |
| 2026-08-11 | PETERS WILLIAM J | CFO, EVP & TREASURER | Sell | 8,180 | $183,886 |
| 2026-07-13 | Pierce Anthony T | Director | Buy | 7,886 | $0 |
| 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 | 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 |
| 2026-03-17 | Luo Mary Z. | COO, Chief Scientist, Chairman | Sell | 9,784 | $177,873 |
| 2026-03-11 | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Buy | 72,462 | $0 |
| 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 |
Source: SEC Form 4 filings · as of 2026-08-12