Amphastar Pharmaceuticals, Inc. — Insider Transactions
Form 4 filings by directors, officers, and 10%+ shareholders
SEC rules require corporate insiders — including directors, executive officers, and any shareholder owning more than 10% of a company's shares — to report changes in their ownership within two business days of a transaction. These disclosures are filed as Form 4. Open-market purchases (code P) are generally considered the most meaningful signal, as insiders are spending their own money.
| Insider | Title | Type | Shares | Price | Value | Owns After | Date |
|---|---|---|---|---|---|---|---|
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Sale | 9,787 | $26.20 | $256,419 | 138,043 | Dec 17, 2025 |
| Petersen Floyd F. | — | Sale | 2,426 | $25.92 | $62,882 | 71,368 | Dec 11, 2025 |
| PRINS RICHARD K | — | Option Exercise | 4,179 | $16.69 | $69,748 | 39,362 | Nov 25, 2025 |
| Petersen Floyd F. | — | Option Exercise | 16,679 | $16.69 | $278,373 | 92,210 | Nov 13, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $25.27 | $12,635 | 75,531 | Nov 3, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $27.20 | $13,600 | 76,031 | Oct 1, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $30.98 | $15,490 | 76,531 | Sep 2, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $20.83 | $10,415 | 77,031 | Aug 1, 2025 |
| Gaugh David Russell | — | Award / Grant | 6,304 | — | — | 6,304 | Jul 18, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $23.47 | $11,735 | 77,531 | Jul 2, 2025 |
| Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Option Exercise | 200,000 | $13.03 | $2,606,000 | 2,847,659 | Jun 13, 2025 |
| Lee Howard | — | Award / Grant | 5,122 | — | — | 152,899 | Jun 3, 2025 |
| Deflin Gayle | — | Award / Grant | 5,122 | — | — | 10,914 | Jun 2, 2025 |
| Gerst Diane G. | — | Award / Grant | 5,122 | — | — | 23,756 | Jun 2, 2025 |
| PRINS RICHARD K | — | Award / Grant | 5,122 | — | — | 35,183 | Jun 2, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $25.67 | $12,835 | 72,909 | Jun 2, 2025 |
| ZASLOFF MICHAEL A | — | Award / Grant | 5,122 | — | — | 29,524 | Jun 2, 2025 |
| PETERS WILLIAM J | CFO, EVP & TREASURER | Tax Withholding | 273 | $24.79 | $6,768 | 124,985 | May 19, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $24.08 | $12,040 | 73,409 | May 1, 2025 |
| Petersen Floyd F. | — | Sale | 500 | $28.38 | $14,190 | 73,909 | Apr 1, 2025 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Tax Withholding | 1,222 | $26.66 | $32,579 | 139,464 | Mar 17, 2025 |
| Liawatidewi Yakob | EVP CORP ADMIN CENTER | Tax Withholding | 1,031 | $26.66 | $27,486 | 92,640 | Mar 17, 2025 |
| PETERS WILLIAM J | CFO, EVP & TREASURER | Tax Withholding | 1,968 | $26.66 | $52,467 | 128,262 | Mar 17, 2025 |
| Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Tax Withholding | 16,150 | $27.69 | $447,194 | 2,647,659 | Mar 14, 2025 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Award / Grant | 24,692 | — | — | 140,686 | Mar 10, 2025 |
| Liawatidewi Yakob | EVP CORP ADMIN CENTER | Award / Grant | 20,837 | — | — | 93,671 | Mar 10, 2025 |
| PETERS WILLIAM J | CFO, EVP & TREASURER | Award / Grant | 36,747 | — | — | 130,230 | Mar 10, 2025 |
| Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Award / Grant | 48,996 | — | — | 1,148,257 | Mar 10, 2025 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Tax Withholding | 1,354 | $28.32 | $38,345 | 115,994 | Mar 6, 2025 |
| PETERS WILLIAM J | CFO, EVP & TREASURER | Tax Withholding | 2,141 | $28.32 | $60,633 | 93,483 | Mar 6, 2025 |
| Liawatidewi Yakob | EVP CORP ADMIN CENTER | Tax Withholding | 1,141 | $28.32 | $32,313 | 72,834 | Mar 6, 2025 |
| Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Tax Withholding | 3,069 | $28.32 | $86,914 | 1,099,261 | Mar 6, 2025 |
| Petersen Floyd F. | — | Sale | 1,000 | $27.99 | $27,990 | 74,409 | Mar 6, 2025 |
| PETERS WILLIAM J | CFO, EVP & TREASURER | Option Exercise | 7,490 | $13.35 | $99,992 | 101,594 | Mar 4, 2025 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Tax Withholding | 1,121 | $27.62 | $30,962 | 117,348 | Mar 4, 2025 |
| Liawatidewi Yakob | EVP CORP ADMIN CENTER | Tax Withholding | 963 | $27.62 | $26,598 | 73,975 | Mar 4, 2025 |
| Luo Mary Z. | COO, Chief Scientist, Chairman | Tax Withholding | 5,753 | $27.62 | $158,898 | 2,502,801 | Mar 4, 2025 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Sale | 7,000 | $44.43 | $311,010 | 118,469 | Dec 13, 2024 |
| PRINS RICHARD K | — | Sale | 10,000 | $43.77 | $437,700 | 30,471 | Dec 9, 2024 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Option Exercise | 6,893 | $14.95 | $103,050 | 125,281 | Nov 12, 2024 |
| PRINS RICHARD K | — | Option Exercise | 2,500 | $16.69 | $41,725 | 36,471 | Nov 12, 2024 |
| Luo Mary Z. | COO, Chief Scientist, Chairman | Gift | 125,000 | — | — | 1,104,756 | Nov 11, 2024 |
| Liawatidewi Yakob | EVP CORP ADMIN CENTER | Sale | 5,214 | $52.05 | $271,389 | 74,938 | Nov 6, 2024 |
| PETERS WILLIAM J | CFO, EVP & TREASURER | Sale | 7,426 | $52.05 | $386,523 | 94,103 | Nov 6, 2024 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Sale | 3,000 | $48.26 | $144,780 | 118,388 | Sep 13, 2024 |
| Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | Option Exercise | 100,000 | $14.69 | $1,469,000 | 2,633,554 | Sep 13, 2024 |
| Petersen Floyd F. | — | Sale | 3,000 | $46.47 | $139,410 | 75,409 | Sep 5, 2024 |
| Zhou Rong | SENIOR EVP, PRODUCTION CENTER | Sale | 4,000 | $48.35 | $193,400 | 118,388 | Aug 26, 2024 |
| PRINS RICHARD K | — | Option Exercise | 6,004 | $20.08 | $120,560 | 43,890 | Aug 12, 2024 |
| PETERS WILLIAM J | CFO, EVP & TREASURER | Option Exercise | 10,282 | $20.23 | $208,005 | 104,385 | Jul 31, 2024 |