Zhang Jack Y. has filed 64 insider transactions across 1 company since March 2023.
Most recent transaction: a tax payment of 9784 shares of Amphastar Pharmaceuticals, Inc. ($AMPH) on March 15, 2026.
| Transaction Date | Company | Ticker | Insider Name | Title | Transaction Type | Security | Shares | Price | Shares Owned Following | Total Shares Outstanding | % of Owned | % of Outstanding |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| March 15, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 9784 | $18.18 | 11,062,856.0000 | 48,215,000 | 0.09% | 0.02% |
| March 15, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 2908 | $18.18 | 11,062,856.0000 | 48,215,000 | 0.03% | 0.01% |
| March 10, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 4395 | $18.91 | 11,075,548.0000 | 48,215,000 | 0.04% | 0.01% |
| March 9, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Common Stock | 72462 | $0.00 | 11,079,943.0000 | 48,215,000 | 0.66% | 0.15% |
| March 10, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 14785 | $18.91 | 11,075,548.0000 | 48,215,000 | 0.13% | 0.03% |
| March 9, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Common Stock | 180504 | $0.00 | 11,090,333.0000 | 48,215,000 | 1.65% | 0.37% |
| March 9, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Employee Stock Option (right to buy) | 372338 | $0.00 | 521,810.0000 | 48,215,000 | 249.10% | 0.77% |
| March 9, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Employee Stock Option (right to buy) | 149472 | $0.00 | 521,810.0000 | 48,215,000 | 40.14% | 0.31% |
| March 6, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 7773 | $19.34 | 10,841,762.0000 | 48,215,000 | 0.07% | 0.02% |
| March 6, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 3077 | $19.34 | 10,841,762.0000 | 48,215,000 | 0.03% | 0.01% |
| March 4, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 5769 | $19.96 | 10,852,612.0000 | 48,215,000 | 0.05% | 0.01% |
| March 4, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 2432 | $19.96 | 10,852,612.0000 | 48,215,000 | 0.02% | 0.01% |
| June 13, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Employee Stock Option (right to buy) | 200000 | $0.00 | 205,003.0000 | 49,890,000 | 49.38% | 0.40% |
| June 13, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Common Stock | 200000 | $13.03 | 10,860,813.0000 | 49,890,000 | 1.88% | 0.40% |
| March 14, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Common Stock | 211213 | $14.69 | 10,834,808.0000 | 52,058,000 | 1.99% | 0.41% |
| March 14, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Common Stock | 290477 | $14.69 | 10,913,013.0000 | 52,058,000 | 2.73% | 0.56% |
| March 14, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 226285 | $26.66 | 10,686,728.0000 | 52,058,000 | 2.07% | 0.43% |
| March 15, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 9765 | $26.66 | 10,676,963.0000 | 52,058,000 | 0.09% | 0.02% |
| March 17, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 16150 | $27.69 | 10,660,813.0000 | 52,058,000 | 0.15% | 0.03% |
| March 14, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 162657 | $26.66 | 10,672,151.0000 | 52,058,000 | 1.50% | 0.31% |
| March 15, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 4115 | $26.66 | 10,668,036.0000 | 52,058,000 | 0.04% | 0.01% |
| March 17, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 7223 | $27.69 | 10,660,813.0000 | 52,058,000 | 0.07% | 0.01% |
| March 14, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Employee Stock Option (right to buy) | 290477 | $0.00 | 0.0000 | 52,058,000 | 100.00% | 0.56% |
| March 14, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Employee Stock Option (right to buy) | 211213 | $0.00 | 0.0000 | 52,058,000 | 100.00% | 0.41% |
| March 10, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Common Stock | 116226 | $0.00 | 10,585,318.0000 | 52,058,000 | 1.11% | 0.22% |
| March 10, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Common Stock | 48996 | $0.00 | 10,585,318.0000 | 52,058,000 | 0.47% | 0.09% |
| March 10, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Employee Stock Option (right to buy) | 246821 | $0.00 | 350,873.0000 | 52,058,000 | 237.21% | 0.47% |
| March 10, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Employee Stock Option (right to buy) | 104052 | $0.00 | 350,873.0000 | 52,058,000 | 42.16% | 0.20% |
| March 6, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 9645 | $28.32 | 10,420,096.0000 | 52,058,000 | 0.09% | 0.02% |
| March 6, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 3069 | $28.32 | 10,420,096.0000 | 52,058,000 | 0.03% | 0.01% |
| March 4, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 2426 | $27.62 | 10,432,810.0000 | 52,058,000 | 0.02% | 0.00% |
| March 4, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | F | Common Stock | 5753 | $27.62 | 10,432,810.0000 | 52,058,000 | 0.06% | 0.01% |
| Nov. 11, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | G | Common Stock | 125000 | $0.00 | 10,440,989.0000 | 51,862,000 | 1.18% | 0.24% |
| Nov. 11, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | G | Common Stock | 125000 | $0.00 | 10,440,989.0000 | 51,862,000 | 1.18% | 0.24% |
| Sept. 13, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Common Stock | 100000 | $14.69 | 10,690,989.0000 | 52,046,000 | 0.94% | 0.19% |
| Sept. 13, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Employee Stock Option (right to buy) | 100000 | $0.00 | 290,477.0000 | 52,046,000 | 25.61% | 0.19% |
| June 10, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Common Stock | 100000 | $14.69 | 10,590,989.0000 | 53,013,000 | 0.95% | 0.19% |
| June 10, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | M | Employee Stock Option (right to buy) | 100000 | $0.00 | 390,477.0000 | 53,013,000 | 20.39% | 0.19% |
| March 15, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | M | Common Stock | 722046 | $12.46 | 10,915,478.0000 | 53,001,000 | 7.08% | 1.36% |
| March 15, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 408721 | $43.05 | 10,506,757.0000 | 53,001,000 | 3.74% | 0.77% |
| March 17, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 15768 | $43.05 | 10,490,989.0000 | 53,001,000 | 0.15% | 0.03% |
| March 15, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | M | Common Stock | 310930 | $12.46 | 10,700,699.0000 | 53,001,000 | 2.99% | 0.59% |
| March 15, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 202658 | $43.05 | 10,498,041.0000 | 53,001,000 | 1.89% | 0.38% |
| March 15, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | M | Employee Stock Option (right to buy) | 722046 | $0.00 | 0.0000 | 53,001,000 | 100.00% | 1.36% |
| March 17, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 7052 | $43.05 | 10,490,989.0000 | 53,001,000 | 0.07% | 0.01% |
| March 15, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | M | Employee Stock Option (right to buy) | 310930 | $0.00 | 0.0000 | 53,001,000 | 100.00% | 0.59% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 7031 | $46.31 | 10,092,212.0000 | 53,001,000 | 0.07% | 0.01% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 2990 | $46.31 | 10,092,212.0000 | 53,001,000 | 0.03% | 0.01% |
| March 4, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Employee Stock Option (right to buy) | 57109 | $0.00 | 192,582.0000 | 53,001,000 | 42.16% | 0.11% |
| March 4, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Common Stock | 64310 | $0.00 | 10,102,233.0000 | 53,001,000 | 0.64% | 0.12% |
| March 4, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Common Stock | 27110 | $0.00 | 10,102,233.0000 | 53,001,000 | 0.27% | 0.05% |
| March 4, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & CHIEF SCIENTIFIC OFFICER | A | Employee Stock Option (right to buy) | 135473 | $0.00 | 192,582.0000 | 53,001,000 | 237.22% | 0.26% |
| March 16, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 9998 | $37.60 | 10,374,051.0000 | 52,427,000 | 0.10% | 0.02% |
| March 17, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 7052 | $36.29 | 10,366,999.0000 | 52,427,000 | 0.07% | 0.01% |
| March 17, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 15768 | $36.29 | 10,366,999.0000 | 52,427,000 | 0.15% | 0.03% |
| March 16, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 25241 | $37.60 | 10,382,767.0000 | 52,427,000 | 0.24% | 0.05% |
| March 16, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | G | Common Stock | 57365 | $0.00 | 8,911,397.0000 | 52,427,000 | 0.64% | 0.11% |
| March 16, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | G | Common Stock | 57365 | $0.00 | 8,911,397.0000 | 52,427,000 | 0.64% | 0.11% |
| March 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 2803 | $36.84 | 10,539,788.0000 | 52,427,000 | 0.03% | 0.01% |
| March 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | F | Common Stock | 8434 | $36.84 | 10,539,788.0000 | 52,427,000 | 0.08% | 0.02% |
| March 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | A | Common Stock | 81383 | $0.00 | 10,551,025.0000 | 52,427,000 | 0.78% | 0.16% |
| March 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | A | Employee Stock Option (right to buy) | 72278 | $0.00 | 243,766.0000 | 52,427,000 | 42.15% | 0.14% |
| March 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | A | Employee Stock Option (right to buy) | 171488 | $0.00 | 243,766.0000 | 52,427,000 | 237.26% | 0.33% |
| March 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | Zhang Jack Y. | CEO & Chief Scientific Officer | A | Common Stock | 34301 | $0.00 | 10,551,025.0000 | 52,427,000 | 0.33% | 0.07% |