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.
The Amphastar Pharmaceuticals, Inc. (NASDAQ: AMPH) SEC filings page on Stock Titan provides access to the company’s official regulatory disclosures as filed with the U.S. Securities and Exchange Commission. Amphastar is a biopharmaceutical company focused on complex generic and proprietary injectable, inhalation, and intranasal products and insulin API products, and its filings offer detailed insight into how this business is structured and governed.
Investors reviewing AMPH filings will find current reports on Form 8-K that describe material events such as license agreements, contract research agreements, manufacturing and distribution amendments, and related-party transactions with entities affiliated with Nanjing Hanxin Pharmaceutical Technology Co., Ltd. These 8-Ks outline key terms for agreements covering proprietary peptides, AMP-110, recombinant peptide research cell banks for AMP-107, and regional distribution of BAQSIMI®.
Amphastar also files earnings-related 8-Ks that furnish press releases summarizing quarterly financial results, including net revenues, net income, and non-GAAP measures such as adjusted net income and adjusted diluted EPS. These disclosures explain how the company evaluates its operating performance and reconcile non-GAAP metrics to GAAP figures.
Through Stock Titan, users can monitor real-time updates from EDGAR as new Amphastar filings appear, including annual reports on Form 10-K and quarterly reports on Form 10-Q when available. AI-powered summaries help explain the significance of complex agreements, highlight changes in licensing and manufacturing arrangements, and surface important details about pipeline assets, manufacturing footprint, distribution partnerships, and governance matters. The filings page also makes it easier to track board and management changes, share repurchase authorizations, and other corporate actions that Amphastar reports to the SEC.
Amphastar Pharmaceuticals Inc received an amended Schedule 13G/A from The Vanguard Group reporting that Vanguard beneficially owns 0 shares of Amphastar common stock as disclosed in the amendment dated 03/13/2026 and signed 03/26/2026.
The filing explains this zero ownership reflects an internal realignment at The Vanguard Group, Inc.; certain subsidiaries or business divisions now report beneficial ownership separately in reliance on SEC Release No. 34-39538 (January 12, 1998). The amendment lists Vanguard's voting and dispositive powers as 0 and states Vanguard's aggregate ownership is 0% of the class.
Amphastar Pharmaceuticals director and EVP Liawatidewi Yakob reported a tax-withholding share disposition related to RSU vesting. On 2026-03-15, 1,033 shares of Common Stock were withheld at $18.18 per share to cover her tax liability from vested restricted stock units.
After this non-market tax-withholding event, she directly holds 121,892 shares of Amphastar Common Stock. An additional 2,459 shares are held indirectly by the Yakob and Sunmoon Trust dated July 25, 2013, for which she serves as a trustee.
Amphastar Pharmaceuticals senior executive Rong Zhou reported a routine tax-withholding share disposition tied to restricted stock units. On March 15, 2026, 1,225 shares of common stock were withheld at $18.18 per share to satisfy tax liabilities from RSU vesting.
After this transaction, Zhou directly held 171,554 Amphastar shares. Footnotes show additional indirect holdings of 99,668 shares held by the Zhou Family Trust, where Zhou serves as trustee, and 5,000 shares held by Zhou’s spouse.
Amphastar Pharmaceuticals CFO William J. Peters reported a routine tax-related share disposition. On the vesting of restricted stock units, 1,973 shares of common stock were withheld at $18.18 per share to satisfy his tax liability, rather than sold on the open market.
After this withholding, Peters directly holds 175,063 shares of Amphastar common stock. This filing reflects a compensation-driven, non-discretionary tax-withholding event, not an open-market purchase or sale decision.
Amphastar Pharmaceuticals reported insider share movements tied to routine tax withholding on vested restricted stock units. On the reported date, entities associated with executives Jack Y. Zhang and Mary Z. Luo delivered a total of 12,692 shares of common stock at $18.18 per share to satisfy tax liabilities, classified as tax-withholding dispositions rather than open-market sales.
Following these transactions, Zhang is shown holding 2,990,052 shares directly, while related entities report 6,827,679 shares held indirectly. Luo-related holdings include 1,245,125 shares held of record. These entries reflect compensation-related mechanics and leave substantial equity positions in place.
Amphastar Pharmaceuticals reported that its Board of Directors authorized a $50 million increase to the company’s share buyback program, effective March 12, 2026. The program is intended primarily to offset dilution from equity compensation grants over time.
Repurchases may occur over an indefinite period through open-market purchases, private block trades, Rule 10b5-1 plans, privately negotiated deals, or other methods permitted by law. The timing and actual number of shares bought back will depend on the share price, corporate and regulatory requirements, and other conditions.
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.