As of March 23, 2026, the three largest insider holders of AMPH are Jack Y. Zhang (Ceo Chief Scientific Officer, 4.25Mn shares), Mary Z. Luo (Coo,Chief Scientist Chairman, 1.10Mn shares), Richard Koo (Director, 259.29K shares).
| Holder | Position | Shares (Direct) | Shares (Indirect) | Report Date |
|---|---|---|---|---|
| Jack Y. Zhang | Ceo Chief Scientific Officer | 2,990,052 | 1,245,125 | 17 Mar, 2026 |
| Mary Z. Luo | Coo,Chief Scientist Chairman | 1,104,416 | 0 | 11 Jan, 2024 |
| Richard Koo | 259,289 | 0 | 08 Jun, 2021 | |
| William J Peters | Cfo, Evp Treasurer | 175,063 | 0 | 17 Mar, 2026 |
| Rong Zhou | Senior Evp, Production Center | 171,554 | 0 | 17 Mar, 2026 |
| Howard Lee | 151,976 | 0 | 04 Jun, 2025 | |
| Yakob Liawatidewi | Evp Corp Admin Center | 121,892 | 0 | 17 Mar, 2026 |
| Floyd F. Petersen | 71,368 | 0 | 15 Dec, 2025 | |
| Richard K Prins | 35,183 | 0 | 25 Nov, 2025 | |
| Michael A Zasloff | 29,524 | 0 | 04 Jun, 2025 | |
| Diane G. Gerst | 23,756 | 0 | 04 Jun, 2025 | |
| David Maris | 19,170 | 0 | 08 Jun, 2021 | |
| Gayle Deflin | 10,914 | 0 | 04 Jun, 2025 | |
| David Russell Gaugh | 6,304 | 0 | 22 Jul, 2025 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 15 Mar, 2026 | Rong Zhou | Common Stock | D | 1,225 | $18.18 | 171,554 | D | F |
| 15 Mar, 2026 | Jack Y. Zhang | Common Stock | D | 9,784 | $18.18 | 2,990,052 | D | F |
| 15 Mar, 2026 | William J Peters | Common Stock | D | 1,973 | $18.18 | 175,063 | D | F |
| 15 Mar, 2026 | Yakob Liawatidewi | Common Stock | D | 1,033 | $18.18 | 121,892 | D | F |
| 15 Mar, 2026 | Jack Y. Zhang | Common Stock | D | 2,908 | $18.18 | 1,245,125 | I | F |
| 09 Mar, 2026 | William J Peters | Common Stock | A | 58,693 | $0.00 | 180,333 | D | A |
| 09 Mar, 2026 | Yakob Liawatidewi | Common Stock | A | 35,450 | $0.00 | 124,795 | D | A |
| 09 Mar, 2026 | Rong Zhou | Common Srock | A | 39,432 | $0.00 | 174,994 | D | A |
| 09 Mar, 2026 | Jack Y. Zhang | Common Stock | A | 180,504 | $0.00 | 3,014,621 | D | A |
| 10 Mar, 2026 | Jack Y. Zhang | Common Stock | D | 14,785 | $18.91 | 2,999,836 | D | F |
| 10 Mar, 2026 | Rong Zhou | Common Stock | D | 2,215 | $18.91 | 172,779 | D | F |
| 10 Mar, 2026 | Yakob Liawatidewi | Common Stock | D | 1,870 | $18.91 | 122,925 | D | F |
| 10 Mar, 2026 | William J Peters | Common Stock | D | 3,297 | $18.91 | 177,036 | D | F |
| 09 Mar, 2026 | Jack Y. Zhang | Common Stock | A | 72,462 | $0.00 | 1,252,428 | I | A |
| 09 Mar, 2026 | William J Peters | Employee Stock Option (right to buy) | A | 121,071 | $0.00 | 121,071 | D | A |
| 09 Mar, 2026 | Yakob Liawatidewi | Employee Stock Option (right to buy) | A | 73,126 | $0.00 | 73,126 | D | A |
| 10 Mar, 2026 | Jack Y. Zhang | Common Stock | D | 4,395 | $18.91 | 1,248,033 | I | F |
| 09 Mar, 2026 | Rong Zhou | Employee Stock Option (right to buy) | A | 81,341 | $0.00 | 81,341 | D | A |
| 09 Mar, 2026 | Jack Y. Zhang | Employee Stock Option (right to buy) | A | 372,338 | $0.00 | 372,338 | D | A |
| 09 Mar, 2026 | Jack Y. Zhang | Employee Stock Option (right to buy) | A | 149,472 | $0.00 | 149,472 | I | A |