Form 4: Amphastar Executives Withhold Shares for Tax on RSU Vesting

Amphastar Pharmaceuticals' CEO and COO withheld a total of 12,692 shares of common stock to cover tax liabilities related to restricted stock unit vesting.

Summary

• Jack Y. Zhang, CEO & Chief Scientific Officer, Director, and 10% Owner, disposed of 9,784 shares of Amphastar Pharmaceuticals, Inc. common stock.
• Mary Z. Luo, COO, Chief Scientist, Chairman, Director, and 10% Owner, disposed of 2,908 shares of Amphastar Pharmaceuticals, Inc. common stock.
• These dispositions occurred on March 15, 2026, at a price of $18.18 per share.
• The shares were withheld to satisfy tax liabilities incurred from the vesting of restricted stock units (RSUs).
• Following these transactions, Jack Y. Zhang directly owns 2,990,052 shares and indirectly owns 1,245,125 shares through Mary Z. Luo, and 6,827,679 shares through Applied Physics and Chemistry Laboratories, Inc.
• Mary Z. Luo's indirect ownership of 1,245,125 shares is held of record by her, and she is the wife of Jack Y. Zhang.
• The 6,827,679 shares held by Applied Physics and Chemistry Laboratories, Inc. are indirectly owned by both reporting persons.

Sentiment

Score: 6

Explanation: StockSavvy.ai views this as a routine and expected transaction related to executive compensation. The vesting of RSUs is generally a positive sign of continued executive alignment and performance, despite the necessary tax-related share disposition.

Positives

• Vesting of restricted stock units (RSUs) for key executives indicates continued employment and performance, aligning executive incentives with shareholder interests.

Negatives

• Executives disposed of a total of 12,692 shares, reducing their direct beneficial ownership, although this was for tax purposes.

Risks

• NA

Future Outlook

This Form 4 filing does not contain forward-looking statements or guidance regarding the company's future outlook.

Management Comments

• NA

Industry Context

StockSavvy.ai notes that tax-related dispositions of shares upon RSU vesting are a common occurrence for executives in publicly traded companies and are generally not indicative of a change in management's confidence in the company's prospects. This is a routine compliance filing.

Comparison to Industry Standards

• StockSavvy.ai observes that the practice of withholding shares to cover tax obligations upon RSU vesting is a standard industry practice across various sectors, including pharmaceuticals. Companies like Pfizer (PFE) and Johnson & Johnson (JNJ) frequently report similar Form 4 filings for their executives, reflecting the tax implications of equity compensation plans. The reported share price of $18.18 is specific to Amphastar and its valuation at the time of the transaction.

Management Changes

Corporate Governance

Legal Proceedings

• NA

Related Party Transactions

• Indirect beneficial ownership of 1,245,125 shares by Jack Y. Zhang through his wife, Mary Z. Luo.
• Indirect beneficial ownership of 6,827,679 shares by both reporting persons through Applied Physics and Chemistry Laboratories, Inc., where they are sole owners.

Stakeholder Impact

• Shareholders: Minor dilution from the shares used for tax withholding, but overall, RSU vesting aligns executive interests with long-term company performance.
• Employees: No direct impact on general employees.

Next Steps

• NA

Key Dates

Recommendation

This Form 4 filing details a routine, non-discretionary transaction where executives withheld shares to cover tax liabilities upon RSU vesting. Such transactions are common and do not typically signal a change in company fundamentals or management's outlook. Therefore, it provides no new information to warrant a change in investment recommendation, suggesting a 'hold' position is appropriate based solely on this filing.

Keywords

Amphastar Pharmaceuticals, AMPH, SEC Form 4, Insider Transaction, Restricted Stock Units, RSU Vesting, Tax Withholding, Jack Y. Zhang, Mary Z. Luo, Beneficial Ownership