PETERS WILLIAM J 4

What Happened

• William J. Peters, Amphastar Pharmaceuticals' CFO, EVP & Treasurer and a director, had 1,744 shares withheld to satisfy tax withholding on vested restricted stock units (RSUs). The shares were recorded as disposed at $19.96 per share, for a total value of $34,810.

Key Details

• Transaction date: March 4, 2026
• Price: $19.96 per share
• Total shares withheld/disposed: 1,744 — total value $34,810
• Shares owned after transaction: not specified in the filing
• Footnotes: F1 — shares were withheld to satisfy tax liability on RSU vesting; F2 — filing notes inclusion of 545 shares acquired May 31, 2025 under the company ESPP
• Transaction code: F (tax withholding); filing submitted March 6, 2026 (no late-filing flag shown)

Context

• This was a tax-withholding disposition tied to RSU vesting (a common, administrative action), not an open-market sale intended to take profits. Such withholding is routine and does not necessarily signal the insider's view of the company's prospects.