Zhou Rong 4

What Happened Rong Zhou, Senior EVP of Amphastar Pharmaceuticals, had 1,225 shares withheld on March 15, 2026 to satisfy tax withholding related to the vesting of restricted stock units (RSUs). The shares were valued at $18.18 each, totaling approximately $22,271. This was a tax-withholding disposition (transaction code F), not an open-market sale.

Key Details

• Transaction date: 2026-03-15; Filing date: 2026-03-17 (filed within the typical 2-business-day Form 4 window).
• Shares withheld/disposed: 1,225 at $18.18 per share; total value ≈ $22,271.
• Transaction code: F — payment of exercise price or tax liability (here, tax withholding on RSU vesting).
• Shares owned after transaction: Not specified in the reported excerpt.
• Footnotes: F1 — shares withheld to satisfy tax liability from RSU vesting; F2 — some shares held of record by the Zhou Family Trust (Rong Zhou is trustee); F3 — some shares held of record by the reporting person's spouse.

Context Tax-withholding dispositions are routine when RSUs vest and are generally administrative rather than a signal of insider sentiment. Because the shares were withheld to cover taxes rather than sold on the open market, this transaction does not reflect an active sale for cash proceeds by the insider.