Zhou Rong 4

What Happened
Zhou Rong, Senior EVP, Production Center at Amphastar Pharmaceuticals, received RSU awards on March 9, 2026 totaling 120,773 shares (39,432 shares reported as a direct award and 81,341 shares reported as a derivative award). The grants are reported at $0.00 per share (typical for RSU grants). On March 10, 2026, 2,215 shares were withheld/disposed to satisfy tax withholding at $18.91 per share, generating ~$41,886. Net new RSUs delivered equals 118,558 shares (120,773 granted minus 2,215 withheld).

Key Details

• Transaction dates and amounts:
  • 2026-03-09: Award/acquisition — 39,432 RSUs @ $0.00 and 81,341 RSU-derivative units @ $0.00.
  • 2026-03-10: Tax withholding/disposition (F) — 2,215 shares @ $18.91, proceeds ~$41,886.
• Vesting: RSUs vest in four equal annual installments beginning March 9, 2027 (Footnote F1).
• Withholding: Shares were withheld to satisfy the reporting person’s tax liability on vesting (Footnote F2).
• Holdings of record: Some shares are held by the Zhou Family Trust (F3) and the reporting person’s spouse (F4).
• Filing: Report filed March 11, 2026 — appears timely based on transaction dates.

Context
This is a compensation-related RSU grant, not an open-market purchase or a decision to sell shares; RSUs vest over time, so the award does not represent an immediate bullish or bearish trade. The small disposition on March 10 is a tax-withholding event (common with RSU vesting), not an independent sale for investment purposes. Footnote F5 references a four-year vesting schedule for options if applicable; no option exercise was reported in this filing.