AMPH · Amphastar Pharmaceuticals Inc. Common Stock
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| Jack Y. Zhang CEO & Chief Scientific Officer | ▼ Sell | Tax Withholding | 1,245,125 Shares held | 3/15/2026 | View profile |
| Luo Mary Z. COO,Chief Scientist & Chairman | ▼ Sell | Open Market | 1,104,416 Shares held | 1/10/2024 | View profile |
| William J. Peters CFO, EVP & Treasurer | ▼ Sell | Open Market | 172,846 Shares held | 8/7/2026 | View profile |
| Rong Zhou EVP, Production Center | ▼ Sell | Tax Withholding | 171,554 Shares held | 3/15/2026 | View profile |
| Howard Lee Director | ▼ Sell | Tax Withholding | 159,350 Shares held | 6/2/2026 | View profile |
| Yakob Liawatidewi EVP Corp Admin Center | ▼ Sell | Tax Withholding | 121,892 Shares held | 3/15/2026 | View profile |
| Floyd F. Petersen Director | ▼ Sell | Open Market | 71,368 Shares held | 12/12/2025 | View profile |
| Michael A. Zasloff Director | ▲ Buy | Grant | 37,667 Shares held | 6/1/2026 | View profile |
| Diane G. Gerst Director | ▲ Buy | Grant | 31,899 Shares held | 6/1/2026 | View profile |
| Richard K. Prins Director | ▼ Sell | Open Market | 29,625 Shares held | 8/11/2026 | View profile |
| Gayle Deflin Director | ▲ Buy | Grant | 19,057 Shares held | 6/1/2026 | View profile |
| David Russell Gaugh | ▲ Buy | Grant | 14,447 Shares held | 6/1/2026 | View profile |
| Anthony T. Pierce | ▲ Buy | Grant | 7,886 Shares held | 7/9/2026 | View profile |
Transaction History
| Richard K. Prins | ▼ Sell | Open Market | 7,973 | $162K | 8/11/2026 |
| William J. Peters | ▼ Sell | Open Market | 8,180 | $184K | 8/7/2026 |
| William J. Peters | ▲ Buy | Option Exercise | 5,053 | $100K | 8/7/2026 |
| Anthony T. Pierce | ▲ Buy | Grant | 7,886 | $0 | 7/9/2026 |
| Howard Lee | ▼ Sell | Tax Withholding | 769 | $14K | 6/2/2026 |
| Richard K. Prins | ▲ Buy | Grant | 8,143 | $0 | 6/1/2026 |
| Howard Lee | ▲ Buy | Grant | 8,143 | $0 | 6/1/2026 |
| Michael A. Zasloff | ▲ Buy | Grant | 8,143 | $0 | 6/1/2026 |
| Diane G. Gerst | ▲ Buy | Grant | 8,143 | $0 | 6/1/2026 |
| David Russell Gaugh | ▲ Buy | Grant | 8,143 | $0 | 6/1/2026 |
| Gayle Deflin | ▲ Buy | Grant | 8,143 | $0 | 6/1/2026 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,033 | $19K | 3/15/2026 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,225 | $22K | 3/15/2026 |
| William J. Peters | ▼ Sell | Tax Withholding | 1,973 | $36K | 3/15/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 9,784 | $178K | 3/15/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 2,908 | $53K | 3/15/2026 |
| William J. Peters | ▼ Sell | Tax Withholding | 3,297 | $62K | 3/10/2026 |
| Rong Zhou | ▼ Sell | Tax Withholding | 2,215 | $42K | 3/10/2026 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,870 | $35K | 3/10/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 14,785 | $280K | 3/10/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 4,395 | $83K | 3/10/2026 |
| William J. Peters | ▲ Buy | Grant | 58,693 | $0 | 3/9/2026 |
| Jack Y. Zhang | ▲ Buy | Grant | 180,504 | $0 | 3/9/2026 |
| Rong Zhou | ▲ Buy | Grant | 39,432 | $0 | 3/9/2026 |
| Yakob Liawatidewi | ▲ Buy | Grant | 35,450 | $0 | 3/9/2026 |
| Jack Y. Zhang | ▲ Buy | Grant | 72,462 | $0 | 3/9/2026 |
| William J. Peters | ▼ Sell | Tax Withholding | 2,146 | $42K | 3/6/2026 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,357 | $26K | 3/6/2026 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,144 | $22K | 3/6/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 7,773 | $150K | 3/6/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 3,077 | $60K | 3/6/2026 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 965 | $19K | 3/4/2026 |
| William J. Peters | ▼ Sell | Tax Withholding | 1,744 | $35K | 3/4/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 5,769 | $115K | 3/4/2026 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 2,432 | $49K | 3/4/2026 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,124 | $22K | 3/4/2026 |
| Rong Zhou | ▲ Buy | Option Exercise | 9,787 | $111K | 12/17/2025 |
| Rong Zhou | ▼ Sell | Open Market | 9,787 | $256K | 12/17/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 2,426 | $63K | 12/12/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 1,737 | $45K | 12/11/2025 |
| Richard K. Prins | ▲ Buy | Option Exercise | 4,179 | $70K | 11/25/2025 |
| Richard K. Prins | ▼ Sell | Open Market | 4,179 | $113K | 11/25/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 16,679 | $442K | 11/13/2025 |
| Floyd F. Petersen | ▲ Buy | Option Exercise | 16,679 | $278K | 11/13/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $13K | 11/3/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $14K | 10/1/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $15K | 9/2/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $10K | 8/1/2025 |
| David Russell Gaugh | ▲ Buy | Grant | 6,304 | $0 | 7/18/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $12K | 7/2/2025 |
| Jack Y. Zhang | ▲ Buy | Option Exercise | 200,000 | $2.6M | 6/13/2025 |
| Howard Lee | ▼ Sell | Tax Withholding | 923 | $24K | 6/3/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $13K | 6/2/2025 |
| Howard Lee | ▲ Buy | Grant | 5,122 | $0 | 6/2/2025 |
| Gayle Deflin | ▲ Buy | Grant | 5,122 | $0 | 6/2/2025 |
| Diane G. Gerst | ▲ Buy | Grant | 5,122 | $0 | 6/2/2025 |
| Richard K. Prins | ▲ Buy | Grant | 5,122 | $0 | 6/2/2025 |
| Floyd F. Petersen | ▲ Buy | Grant | 5,122 | $0 | 6/2/2025 |
| Michael A. Zasloff | ▲ Buy | Grant | 5,122 | $0 | 6/2/2025 |
| William J. Peters | ▼ Sell | Tax Withholding | 273 | $7K | 5/19/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $12K | 5/1/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $14K | 4/1/2025 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,967 | $54K | 3/17/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 16,150 | $447K | 3/17/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 7,223 | $200K | 3/17/2025 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,731 | $48K | 3/17/2025 |
| William J. Peters | ▼ Sell | Tax Withholding | 3,004 | $83K | 3/17/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 4,115 | $110K | 3/15/2025 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,222 | $33K | 3/15/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 9,765 | $260K | 3/15/2025 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,031 | $27K | 3/15/2025 |
| William J. Peters | ▼ Sell | Tax Withholding | 1,968 | $52K | 3/15/2025 |
| Jack Y. Zhang | ▲ Buy | Option Exercise | 211,213 | $3.1M | 3/14/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 162,657 | $4.3M | 3/14/2025 |
| Jack Y. Zhang | ▲ Buy | Option Exercise | 290,477 | $4.3M | 3/14/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 226,285 | $6.0M | 3/14/2025 |
| Rong Zhou | ▲ Buy | Grant | 24,692 | $0 | 3/10/2025 |
| Yakob Liawatidewi | ▲ Buy | Grant | 20,837 | $0 | 3/10/2025 |
| William J. Peters | ▲ Buy | Grant | 36,747 | $0 | 3/10/2025 |
| Jack Y. Zhang | ▲ Buy | Grant | 116,226 | $0 | 3/10/2025 |
| Jack Y. Zhang | ▲ Buy | Grant | 48,996 | $0 | 3/10/2025 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,354 | $38K | 3/6/2025 |
| William J. Peters | ▼ Sell | Tax Withholding | 2,141 | $61K | 3/6/2025 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,141 | $32K | 3/6/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 9,645 | $273K | 3/6/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 3,069 | $87K | 3/6/2025 |
| Floyd F. Petersen | ▼ Sell | Open Market | 1,000 | $28K | 3/6/2025 |
| William J. Peters | ▲ Buy | Option Exercise | 7,490 | $100K | 3/4/2025 |
| William J. Peters | ▼ Sell | Open Market | 4,231 | $117K | 3/4/2025 |
| William J. Peters | ▼ Sell | Tax Withholding | 1,739 | $48K | 3/4/2025 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,121 | $31K | 3/4/2025 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 963 | $27K | 3/4/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 5,753 | $159K | 3/4/2025 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 2,426 | $67K | 3/4/2025 |
| Rong Zhou | ▲ Buy | Option Exercise | 8,000 | $91K | 12/13/2024 |
| Rong Zhou | ▼ Sell | Open Market | 8,000 | $362K | 12/13/2024 |
| Rong Zhou | ▲ Buy | Option Exercise | 7,000 | $79K | 12/12/2024 |
| Rong Zhou | ▼ Sell | Open Market | 7,000 | $311K | 12/12/2024 |
| Richard K. Prins | ▲ Buy | Option Exercise | 10,000 | $195K | 12/9/2024 |
| Richard K. Prins | ▼ Sell | Open Market | 10,000 | $438K | 12/9/2024 |
| Richard K. Prins | ▼ Sell | Gift | 410 | $0 | 12/9/2024 |
| Rong Zhou | ▲ Buy | Option Exercise | 6,893 | $103K | 11/12/2024 |
| Rong Zhou | ▼ Sell | Open Market | 6,893 | $337K | 11/12/2024 |
| Richard K. Prins | ▲ Buy | Option Exercise | 2,500 | $42K | 11/12/2024 |
| Richard K. Prins | ▼ Sell | Open Market | 5,000 | $244K | 11/12/2024 |
| Richard K. Prins | ▼ Sell | Gift | 1,000 | $0 | 11/12/2024 |
| Jack Y. Zhang | ▼ Sell | Gift | 125,000 | $0 | 11/11/2024 |
| Jack Y. Zhang | ▼ Sell | Gift | 125,000 | $0 | 11/11/2024 |
| Yakob Liawatidewi | ▲ Buy | Option Exercise | 5,214 | $68K | 11/6/2024 |
| Yakob Liawatidewi | ▼ Sell | Open Market | 5,214 | $271K | 11/6/2024 |
| William J. Peters | ▲ Buy | Option Exercise | 7,426 | $97K | 11/6/2024 |
| William J. Peters | ▼ Sell | Open Market | 7,426 | $387K | 11/6/2024 |
| Rong Zhou | ▲ Buy | Option Exercise | 3,000 | $45K | 9/13/2024 |
| Rong Zhou | ▼ Sell | Open Market | 3,000 | $145K | 9/13/2024 |
| Jack Y. Zhang | ▲ Buy | Option Exercise | 100,000 | $1.5M | 9/13/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 3,000 | $139K | 9/5/2024 |
| Rong Zhou | ▲ Buy | Option Exercise | 4,000 | $60K | 8/26/2024 |
| Rong Zhou | ▼ Sell | Open Market | 4,000 | $193K | 8/26/2024 |
| Richard K. Prins | ▼ Sell | Gift | 1,500 | $0 | 8/19/2024 |
| Richard K. Prins | ▲ Buy | Option Exercise | 3,915 | $78K | 8/12/2024 |
| Richard K. Prins | ▲ Buy | Option Exercise | 6,004 | $121K | 8/12/2024 |
| Richard K. Prins | ▲ Buy | Option Exercise | 7,182 | $140K | 8/12/2024 |
| Richard K. Prins | ▼ Sell | Open Market | 17,101 | $737K | 8/12/2024 |
| William J. Peters | ▲ Buy | Option Exercise | 10,282 | $208K | 7/31/2024 |
| William J. Peters | ▼ Sell | Open Market | 10,282 | $455K | 7/31/2024 |
| William J. Peters | ▼ Sell | Open Market | 2,961 | $121K | 6/27/2024 |
| William J. Peters | ▼ Sell | Open Market | 635 | $26K | 6/27/2024 |
| Jack Y. Zhang | ▲ Buy | Option Exercise | 100,000 | $1.5M | 6/10/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 3,000 | $124K | 6/10/2024 |
| Howard Lee | ▼ Sell | Tax Withholding | 579 | $24K | 6/5/2024 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 272 | $11K | 6/4/2024 |
| Howard Lee | ▲ Buy | Grant | 3,076 | $0 | 6/3/2024 |
| Diane G. Gerst | ▲ Buy | Grant | 3,076 | $0 | 6/3/2024 |
| Gayle Deflin | ▲ Buy | Grant | 3,076 | $0 | 6/3/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $21K | 6/3/2024 |
| Floyd F. Petersen | ▲ Buy | Grant | 3,076 | $0 | 6/3/2024 |
| Richard K. Prins | ▲ Buy | Grant | 3,076 | $0 | 6/3/2024 |
| Michael A. Zasloff | ▲ Buy | Grant | 3,076 | $0 | 6/3/2024 |
| William J. Peters | ▼ Sell | Tax Withholding | 387 | $17K | 5/19/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $21K | 5/1/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 500 | $22K | 4/1/2024 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 15,768 | $679K | 3/17/2024 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 7,052 | $304K | 3/17/2024 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,726 | $74K | 3/17/2024 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,961 | $84K | 3/17/2024 |
| William J. Peters | ▼ Sell | Tax Withholding | 4,255 | $183K | 3/17/2024 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,671 | $72K | 3/16/2024 |
| Rong Zhou | ▼ Sell | Tax Withholding | 2,355 | $101K | 3/16/2024 |
| William J. Peters | ▼ Sell | Tax Withholding | 5,105 | $220K | 3/16/2024 |
| Jack Y. Zhang | ▲ Buy | Option Exercise | 722,046 | $9.0M | 3/15/2024 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 408,721 | $17.6M | 3/15/2024 |
| Jack Y. Zhang | ▲ Buy | Option Exercise | 310,930 | $3.9M | 3/15/2024 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 202,658 | $8.7M | 3/15/2024 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,027 | $44K | 3/15/2024 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,219 | $52K | 3/15/2024 |
| William J. Peters | ▼ Sell | Tax Withholding | 2,285 | $98K | 3/15/2024 |
| William J. Peters | ▲ Buy | Option Exercise | 8,826 | $100K | 3/6/2024 |
| William J. Peters | ▼ Sell | Open Market | 13,404 | $621K | 3/6/2024 |
| William J. Peters | ▼ Sell | Open Market | 4,681 | $220K | 3/6/2024 |
| William J. Peters | ▼ Sell | Open Market | 51 | $2K | 3/6/2024 |
| William J. Peters | ▼ Sell | Tax Withholding | 2,190 | $101K | 3/6/2024 |
| Yakob Liawatidewi | ▼ Sell | Tax Withholding | 1,221 | $57K | 3/6/2024 |
| Rong Zhou | ▼ Sell | Tax Withholding | 1,390 | $64K | 3/6/2024 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 7,031 | $326K | 3/6/2024 |
| Jack Y. Zhang | ▼ Sell | Tax Withholding | 2,990 | $138K | 3/6/2024 |
| Michael A. Zasloff | ▼ Sell | Open Market | 9,389 | $442K | 3/5/2024 |
| Michael A. Zasloff | ▼ Sell | Open Market | 3,111 | $148K | 3/5/2024 |
| Yakob Liawatidewi | ▲ Buy | Grant | 10,754 | $0 | 3/4/2024 |
| Rong Zhou | ▲ Buy | Grant | 12,521 | $0 | 3/4/2024 |
| William J. Peters | ▲ Buy | Grant | 19,440 | $0 | 3/4/2024 |
| Jack Y. Zhang | ▲ Buy | Grant | 27,110 | $0 | 3/4/2024 |
| Jack Y. Zhang | ▲ Buy | Grant | 64,310 | $0 | 3/4/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 451 | $21K | 3/1/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 49 | $2K | 3/1/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 474 | $25K | 2/1/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 26 | $1K | 2/1/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 78,236 | $4.2M | 1/10/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 50,514 | $2.8M | 1/10/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 920 | $51K | 1/10/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 1,716 | $98K | 1/10/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 50,678 | $2.9M | 1/9/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 31,764 | $1.8M | 1/9/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 3,714 | $217K | 1/9/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 27,563 | $1.7M | 1/8/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 4,261 | $261K | 1/8/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 1,663 | $103K | 1/8/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 2,152 | $136K | 1/8/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 18,858 | $1.1M | 1/8/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 41,282 | $2.4M | 1/8/2024 |
| Luo Mary Z. | ▼ Sell | Open Market | 37,865 | $2.2M | 1/8/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 147 | $9K | 1/2/2024 |
| Floyd F. Petersen | ▼ Sell | Open Market | 353 | $22K | 1/2/2024 |
| Rong Zhou | ▲ Buy | Option Exercise | 3,514 | $57K | 12/4/2023 |
| Rong Zhou | ▼ Sell | Open Market | 3,514 | $209K | 12/4/2023 |
| Rong Zhou | ▼ Sell | Open Market | 4,316 | $253K | 12/1/2023 |
| Floyd F. Petersen | ▼ Sell | Open Market | 135 | $8K | 12/1/2023 |
| Floyd F. Petersen | ▼ Sell | Open Market | 365 | $21K | 12/1/2023 |
| Rong Zhou | ▲ Buy | Option Exercise | 4,316 | $62K | 12/1/2023 |
| Richard K. Prins | ▼ Sell | Open Market | 4,000 | $223K | 11/17/2023 |
| Richard K. Prins | ▼ Sell | Gift | 1,000 | $0 | 11/17/2023 |