PETERS WILLIAM J has filed 83 insider transactions across 1 company since March 2023.
Most recent transaction: a tax payment of 1973 shares of Amphastar Pharmaceuticals, Inc. ($AMPH) on March 15, 2026.
Activity breakdown: 0 open-market purchases and 23 sales.
| 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 | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 1973 | $18.18 | 175,063.0000 | 48,215,000 | 1.11% | 0.00% |
| March 9, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | A | Employee Stock Option (right to buy) | 121071 | $0.00 | 121,071.0000 | 48,215,000 | 9999.99% | 0.25% |
| March 10, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 3297 | $18.91 | 177,036.0000 | 48,215,000 | 1.83% | 0.01% |
| March 9, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | A | Common Stock | 58693 | $0.00 | 180,333.0000 | 48,215,000 | 48.25% | 0.12% |
| March 6, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 2146 | $19.34 | 121,640.0000 | 48,215,000 | 1.73% | 0.00% |
| March 4, 2026 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 1744 | $19.96 | 123,786.0000 | 48,215,000 | 1.39% | 0.00% |
| May 19, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 273 | $24.79 | 124,985.0000 | 49,890,000 | 0.22% | 0.00% |
| March 17, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 3004 | $27.69 | 125,258.0000 | 52,058,000 | 2.34% | 0.01% |
| March 15, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 1968 | $26.66 | 128,262.0000 | 52,058,000 | 1.51% | 0.00% |
| March 10, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | A | Employee Stock Option (right to buy) | 78039 | $0.00 | 78,039.0000 | 52,058,000 | 9999.99% | 0.15% |
| March 10, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | A | Common Stock | 36747 | $0.00 | 130,230.0000 | 52,058,000 | 39.31% | 0.07% |
| March 6, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 2141 | $28.32 | 93,483.0000 | 52,058,000 | 2.24% | 0.00% |
| March 4, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 1739 | $27.62 | 95,624.0000 | 52,058,000 | 1.79% | 0.00% |
| March 4, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Employee Stock Option (right to buy) | 7490 | $0.00 | 0.0000 | 52,058,000 | 100.00% | 0.01% |
| March 4, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Common Stock | 7490 | $13.35 | 101,594.0000 | 52,058,000 | 7.96% | 0.01% |
| March 4, 2025 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 4231 | $27.54 | 97,363.0000 | 52,058,000 | 4.16% | 0.01% |
| Nov. 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Employee Stock Option (right to buy) | 7426 | $0.00 | 23,674.0000 | 51,862,000 | 23.88% | 0.01% |
| Nov. 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Common Stock | 7426 | $13.03 | 101,529.0000 | 51,862,000 | 7.89% | 0.01% |
| Nov. 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 7426 | $52.05 | 94,103.0000 | 51,862,000 | 7.31% | 0.01% |
| July 31, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 10282 | $44.23 | 94,103.0000 | 52,046,000 | 9.85% | 0.02% |
| July 31, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Common Stock | 10282 | $20.23 | 104,385.0000 | 52,046,000 | 10.93% | 0.02% |
| July 31, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Employee Stock Option (right to buy) | 10282 | $0.00 | 4,943.0000 | 52,046,000 | 67.53% | 0.02% |
| June 27, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 2961 | $40.85 | 94,738.0000 | 53,013,000 | 3.03% | 0.01% |
| June 27, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 635 | $41.29 | 94,103.0000 | 53,013,000 | 0.67% | 0.00% |
| May 19, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 387 | $43.48 | 97,268.0000 | 53,013,000 | 0.40% | 0.00% |
| March 16, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 5105 | $43.05 | 101,910.0000 | 53,001,000 | 4.77% | 0.01% |
| March 15, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 2285 | $43.05 | 107,015.0000 | 53,001,000 | 2.09% | 0.00% |
| March 17, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 4255 | $43.05 | 97,655.0000 | 53,001,000 | 4.18% | 0.01% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Employee Stock Option (right to buy) | 8826 | $0.00 | 0.0000 | 53,001,000 | 100.00% | 0.02% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | F | Common Stock | 2190 | $46.31 | 109,300.0000 | 53,001,000 | 1.96% | 0.00% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 51 | $48.00 | 111,490.0000 | 53,001,000 | 0.05% | 0.00% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 4681 | $46.98 | 111,541.0000 | 53,001,000 | 4.03% | 0.01% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | S | Common Stock | 13404 | $46.30 | 116,222.0000 | 53,001,000 | 10.34% | 0.03% |
| March 6, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | M | Common Stock | 8826 | $11.33 | 129,626.0000 | 53,001,000 | 7.31% | 0.02% |
| March 4, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | A | Employee Stock Option (right to buy) | 40955 | $0.00 | 40,955.0000 | 53,001,000 | 9999.99% | 0.08% |
| March 4, 2024 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & TREASURER | A | Common Stock | 19440 | $0.00 | 120,800.0000 | 53,001,000 | 19.18% | 0.04% |
| Nov. 14, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 21250 | $0.00 | 15,225.0000 | 53,921,000 | 58.26% | 0.04% |
| Nov. 14, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 38000 | $0.00 | 31,100.0000 | 53,921,000 | 54.99% | 0.07% |
| Nov. 14, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 21250 | $20.23 | 122,610.0000 | 53,921,000 | 20.96% | 0.04% |
| Nov. 14, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 38000 | $13.03 | 160,610.0000 | 53,921,000 | 30.99% | 0.07% |
| Nov. 14, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 30162 | $55.67 | 116,228.0000 | 53,921,000 | 20.60% | 0.06% |
| Nov. 14, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 14220 | $54.76 | 146,390.0000 | 53,921,000 | 8.85% | 0.03% |
| Nov. 14, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 14868 | $56.53 | 101,360.0000 | 53,921,000 | 12.79% | 0.03% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 60684 | $51.75 | 101,419.0000 | 53,102,000 | 37.44% | 0.11% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 10000 | $19.79 | 115,603.0000 | 53,102,000 | 9.47% | 0.02% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 21250 | $20.23 | 136,853.0000 | 53,102,000 | 18.38% | 0.04% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 25250 | $13.03 | 162,103.0000 | 53,102,000 | 18.45% | 0.05% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 59 | $52.26 | 101,360.0000 | 53,102,000 | 0.06% | 0.00% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 10000 | $0.00 | 5,053.0000 | 53,102,000 | 66.43% | 0.02% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 21250 | $0.00 | 36,475.0000 | 53,102,000 | 36.81% | 0.04% |
| Sept. 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 25250 | $0.00 | 69,100.0000 | 53,102,000 | 26.76% | 0.05% |
| June 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 12000 | $50.79 | 118,603.0000 | 51,970,000 | 9.19% | 0.02% |
| June 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 13000 | $52.79 | 105,603.0000 | 51,970,000 | 10.96% | 0.03% |
| June 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 36868 | $0.00 | 15,053.0000 | 51,970,000 | 71.01% | 0.07% |
| June 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 36868 | $19.79 | 142,471.0000 | 51,970,000 | 34.91% | 0.07% |
| June 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 11868 | $48.79 | 130,603.0000 | 51,970,000 | 8.33% | 0.02% |
| June 2, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 11000 | $13.35 | 116,603.0000 | 51,970,000 | 10.42% | 0.02% |
| June 2, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 11000 | $46.35 | 105,603.0000 | 51,970,000 | 9.43% | 0.02% |
| June 2, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 11000 | $0.00 | 7,490.0000 | 51,970,000 | 59.49% | 0.02% |
| May 19, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | F | Common Stock | 378 | $44.16 | 104,770.0000 | 51,970,000 | 0.36% | 0.00% |
| May 18, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 10500 | $0.00 | 18,490.0000 | 51,970,000 | 36.22% | 0.02% |
| May 18, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 10500 | $13.35 | 115,648.0000 | 51,970,000 | 9.99% | 0.02% |
| May 18, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 10500 | $44.35 | 105,148.0000 | 51,970,000 | 9.08% | 0.02% |
| April 17, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 5632 | $42.35 | 105,148.0000 | 51,970,000 | 5.08% | 0.01% |
| April 17, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 5632 | $0.00 | 28,990.0000 | 51,970,000 | 16.27% | 0.01% |
| April 17, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 5632 | $13.35 | 110,780.0000 | 51,970,000 | 5.36% | 0.01% |
| April 13, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 4868 | $13.35 | 110,016.0000 | 51,970,000 | 4.63% | 0.01% |
| April 13, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 4868 | $42.35 | 105,148.0000 | 51,970,000 | 4.42% | 0.01% |
| April 13, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 4868 | $0.00 | 34,622.0000 | 51,970,000 | 12.33% | 0.01% |
| April 10, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 10032 | $0.00 | 39,490.0000 | 51,970,000 | 20.26% | 0.02% |
| April 10, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 10032 | $13.35 | 115,180.0000 | 51,970,000 | 9.54% | 0.02% |
| April 10, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 10032 | $40.35 | 105,148.0000 | 51,970,000 | 8.71% | 0.02% |
| March 16, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | F | Common Stock | 4995 | $37.60 | 109,310.0000 | 52,427,000 | 4.37% | 0.01% |
| March 17, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | F | Common Stock | 4162 | $36.29 | 105,148.0000 | 52,427,000 | 3.81% | 0.01% |
| March 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 6688 | $0.00 | 0.0000 | 52,427,000 | 100.00% | 0.01% |
| March 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 6688 | $14.95 | 131,227.0000 | 52,427,000 | 5.37% | 0.01% |
| March 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 12776 | $36.43 | 118,451.0000 | 52,427,000 | 9.74% | 0.02% |
| March 15, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | F | Common Stock | 4146 | $36.84 | 114,305.0000 | 52,427,000 | 3.50% | 0.01% |
| March 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | A | Common Stock | 23925 | $0.00 | 124,539.0000 | 52,427,000 | 23.78% | 0.05% |
| March 6, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | A | Employee Stock Option (right to buy) | 50416 | $0.00 | 50,416.0000 | 52,427,000 | 9999.99% | 0.10% |
| March 1, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Common Stock | 10974 | $11.33 | 111,588.0000 | 52,427,000 | 10.91% | 0.02% |
| March 1, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | S | Common Stock | 10974 | $36.33 | 100,614.0000 | 52,427,000 | 9.83% | 0.02% |
| March 1, 2023 | Amphastar Pharmaceuticals, Inc. | $AMPH | PETERS WILLIAM J | CFO, EVP & Treasurer | M | Employee Stock Option (right to buy) | 10974 | $0.00 | 8,826.0000 | 52,427,000 | 55.42% | 0.02% |