William J. Peters

Companies

• Amphastar Pharmaceuticals, Inc.Board member Apr 12, 2023 to now¹
• Amphastar Pharmaceuticals, Inc.Chief financial officer Jun 24, 2014 to now²

Holdings

Stock this person has reported owning, from the forms officers and directors file with the SEC. See the biggest insider stakes.

Shares held

• APAmphastar Pharmaceuticals, Inc. AMPH168,707 shares³$4.4M at $26.00Sep 21, 2026

As of each latest filing. The line shows shares held over time.

Recent filings

• Sep 21, 2026Sold 4,139 shares at $25.00 of Amphastar Pharmaceuticals, Inc.³
• Aug 7, 2026Sold 8,180 shares at $22.48 of Amphastar Pharmaceuticals, Inc.⁴
• Aug 7, 2026Exercised options 5,053 shares at $19.79 of Amphastar Pharmaceuticals, Inc.⁴
• Mar 15, 2026Shares withheld for tax 1,973 shares at $18.18 of Amphastar Pharmaceuticals, Inc.⁵
• Mar 10, 2026Shares withheld for tax 3,297 shares at $18.91 of Amphastar Pharmaceuticals, Inc.⁶
• Mar 9, 2026Granted 58,693 shares of Amphastar Pharmaceuticals, Inc.⁶
• Mar 6, 2026Shares withheld for tax 2,146 shares at $19.34 of Amphastar Pharmaceuticals, Inc.⁷
• Mar 4, 2026Shares withheld for tax 1,744 shares at $19.96 of Amphastar Pharmaceuticals, Inc.⁸
• May 19, 2025Shares withheld for tax 273 shares at $24.79 of Amphastar Pharmaceuticals, Inc.⁹
• Mar 17, 2025Shares withheld for tax 3,004 shares at $27.69 of Amphastar Pharmaceuticals, Inc.¹⁰
• Mar 15, 2025Shares withheld for tax 1,968 shares at $26.66 of Amphastar Pharmaceuticals, Inc.¹⁰
• Mar 10, 2025Granted 36,747 shares of Amphastar Pharmaceuticals, Inc.¹¹
• Mar 6, 2025Shares withheld for tax 2,141 shares at $28.32 of Amphastar Pharmaceuticals, Inc.¹²
• Mar 4, 2025Shares withheld for tax 1,739 shares at $27.62 of Amphastar Pharmaceuticals, Inc.¹³
• Mar 4, 2025Sold 4,231 shares at $27.54 of Amphastar Pharmaceuticals, Inc.¹³
• Mar 4, 2025Exercised options 7,490 shares at $13.35 of Amphastar Pharmaceuticals, Inc.¹³
• Nov 6, 2024Sold 7,426 shares at $52.05 of Amphastar Pharmaceuticals, Inc.¹⁴
• Nov 6, 2024Exercised options 7,426 shares at $13.03 of Amphastar Pharmaceuticals, Inc.¹⁴
• Jul 31, 2024Sold 10,282 shares at $44.23 of Amphastar Pharmaceuticals, Inc.¹⁵
• Jul 31, 2024Exercised options 10,282 shares at $20.23 of Amphastar Pharmaceuticals, Inc.¹⁵
• Jun 27, 2024Sold 635 shares at $41.29 of Amphastar Pharmaceuticals, Inc.¹⁶
• Jun 27, 2024Sold 2,961 shares at $40.85 of Amphastar Pharmaceuticals, Inc.¹⁶
• May 19, 2024Shares withheld for tax 387 shares at $43.48 of Amphastar Pharmaceuticals, Inc.¹⁷
• Mar 17, 2024Shares withheld for tax 4,255 shares at $43.05 of Amphastar Pharmaceuticals, Inc.¹⁸
• Mar 16, 2024Shares withheld for tax 5,105 shares at $43.05 of Amphastar Pharmaceuticals, Inc.¹⁸