Welcome to our dedicated page for Amphastar Pharma SEC filings (Ticker: AMPH), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Amphastar Pharmaceuticals filings document the regulatory disclosures of a Delaware biopharmaceutical company focused on generic and proprietary injectable, inhalation, and intranasal products, along with active pharmaceutical ingredient products. Form 8-K reports furnish operating results, product revenue commentary, non-GAAP measures, and material business updates tied to the company's pharmaceutical products business.
Amphastar's SEC filings also cover governance and capital-structure matters, including proxy disclosures, executive compensation, employment agreements, equity-compensation dilution, and share repurchase authorizations. Material agreement filings describe licensing rights for a corticotropin compound, supply arrangements involving a Chinese subsidiary, related-party review procedures, and commercial terms that affect the company's pipeline, manufacturing, and distribution activities.
Amphastar Pharmaceuticals CFO William J. Peters reported equity compensation and related tax withholding transactions. On March 9, 2026, he received 58,693 shares of Common Stock in the form of restricted stock units that vest in four equal annual installments beginning on March 9, 2027.
On the same date, he was granted an employee stock option covering 121,071 shares of Common Stock at an exercise price of $19.21 per share, expiring in 2036, also vesting in four equal annual installments beginning on March 9, 2027. On March 10, 2026, 3,297 shares of Common Stock were withheld to cover his tax liabilities from RSU vesting, leaving him with 177,036 shares of Common Stock held directly.
Amphastar Pharmaceuticals, Inc. senior executive Rong Zhou reported routine equity compensation and related tax withholding. On March 9, 2026, Zhou received 39,432 restricted stock units (RSUs) and an option for 81,341 shares of common stock at $19.21 per share, both vesting in four equal annual installments beginning on March 9, 2027. A separate entry on March 10, 2026 shows 2,215 common shares withheld at $18.91 per share to cover taxes on RSU vesting, which is characterized as a tax-withholding disposition rather than an open-market sale. After these transactions, Zhou holds 172,779 common shares directly, in addition to indirect holdings of 99,668 shares through the Zhou Family Trust and 5,000 shares held by a spouse, plus the newly granted option for 81,341 shares.
Amphastar Pharmaceuticals EVP Liawatidewi Yakob reported routine equity compensation and related tax withholding. She received 35,450 shares of Common Stock in the form of restricted stock units that vest in four equal annual installments beginning on March 9, 2027. She was also granted employee stock options for 73,126 shares of Common Stock at an exercise price of $19.21 per share, vesting in four equal annual installments starting on March 9, 2027 and expiring in 2036. In connection with RSU vesting, 1,870 shares of Common Stock were withheld to satisfy tax liabilities, a non‑market disposition. Following these events, she holds 122,925 Common Stock shares directly, 2,459 shares indirectly through the Yakob and Sunmoon Trust, and the newly granted 73,126 stock options.
Amphastar Pharmaceuticals insiders reported routine equity compensation and related tax withholding. CEO Jack Y. Zhang and COO Mary Z. Luo, who are also major shareholders and directors, received grants of restricted stock units (RSUs) and employee stock options tied to common stock. The RSUs, totaling 180,504 shares held directly and 72,462 shares held indirectly, vest in four equal annual installments beginning on March 9, 2027. They also received employee stock options for 372,338 shares held directly and 149,472 shares held indirectly, with a $19.21 exercise price and the same four-year vesting schedule. In connection with RSU vesting, 14,785 directly held shares and 4,395 indirectly held shares of common stock were withheld at $18.91 per share to cover tax liabilities, a non‑market transaction. Following these updates, reported holdings include 3,014,621 shares of common stock held directly, 1,252,428 shares held indirectly, and 6,827,679 additional shares held indirectly through Applied Physics and Chemistry Laboratories, Inc. and a related trust.
Amphastar Pharmaceuticals director and CFO William J. Peters reported a routine tax-related share disposition. On March 6, 2026, 2,146 shares of common stock were withheld at $19.34 per share to satisfy his tax liability from vesting restricted stock units. After this withholding, he directly owned 121,640 shares of Amphastar common stock.
Amphastar Pharmaceuticals senior executive Rong Zhou reported a routine tax-related share disposition. On March 6, 2026, 1,357 shares of common stock were withheld at $19.34 per share to cover taxes from vesting restricted stock units. After this withholding, Zhou directly held 135,562 shares, with additional indirect holdings of 99,668 shares through the Zhou Family Trust and 5,000 shares held by the spouse, as noted in the footnotes. This filing reflects compensation- and tax-driven activity rather than an open-market trade.
Amphastar Pharmaceuticals EVP Liawatidewi Yakob reported a routine tax-related share disposition. On March 6, 2026, 1,144 shares of common stock were withheld at $19.34 per share to cover taxes on vesting restricted stock units, not as an open-market sale.
After this withholding, Yakob directly holds 89,345 shares of Amphastar common stock and indirectly holds 2,459 shares through the Yakob and Sunmoon Trust dated July 25, 2013, where she serves as trustee.
Amphastar Pharmaceuticals director and CEO Jack Y. Zhang reported routine tax-related share withholdings tied to restricted stock unit vesting. On March 6, 2026, a total of 10,850 shares of common stock were withheld to satisfy tax liabilities, rather than sold on the open market.
After these withholdings, Zhang holds 2,834,117 shares directly. Additional indirect holdings include 1,179,966 shares held of record by his spouse, Mary Z. Luo, and 6,827,679 shares held through Applied Physics and Chemistry Laboratories, Inc. and a related family trust.
Amphastar Pharmaceuticals insiders reported tax-related share withholdings tied to equity compensation, not open-market sales. CEO and Chief Scientific Officer Jack Y. Zhang had 5,769 shares of common stock withheld at $19.96 per share to satisfy tax liabilities from vesting restricted stock units, leaving 2,841,890 shares held directly.
Additional tax-withholding dispositions of 2,432 common shares at $19.96 per share were reported as indirectly owned, with 1,183,043 indirect shares remaining. Footnotes state that some securities are held of record by Mary Z. Luo and that 6,827,679 shares are held of record by Applied Physics and Chemistry Laboratories, Inc., which is owned by the reporting persons and The Bill Luobei Zhang 2004 Irrevocable Trust.
Amphastar Pharmaceuticals senior executive Rong Zhou reported a small share disposition related to taxes, not an open-market sale. On the RSU vesting date, 1,124 shares of common stock were withheld at $19.96 per share to cover Zhou’s tax liability, leaving 136,919 shares held directly. In addition, 99,668 shares are held indirectly through the Zhou Family Trust, where Zhou serves as trustee, and 5,000 shares are held by Zhou’s spouse.