Form4insider filings, from the source

Insider holders · CIK 0001297184

Amphastar Pharmaceuticals, Inc. · AMPH

Every insider with a reported Table I holding at this company, ranked by their last-reported share count. A balance is only as fresh as its filing — the report date sits next to every row on purpose. ← Back to activity

InsiderDirect sharesIndirect sharesTotal reportedLast report (ET)From
Applied Physics & Chemistry Laboratories, Inc.10% Owner7,327,679—7,327,679Dec 13, 2018 · 8:05 pm ESTForm 4
Jack Y. ZhangCEO & Chief Scientific Officer2,072,317200,0002,272,317Dec 17, 2018 · 8:02 pm ESTForm 4
Mary Z. LuoCOO,Chief Scientist & Chairman2,072,317200,0002,272,317Dec 17, 2018 · 8:02 pm ESTForm 4
Richard KooDirector241,92810,000251,928Dec 12, 2018 · 8:39 pm ESTForm 4
Rong ZhouSENIOR EVP, PRODUCTION CENTER169,2035,000174,203Sep 17, 2026 · 6:19 pm EDTForm 4
William J PetersCFO, EVP & TREASURER168,707—168,707Sep 23, 2026 · 6:02 pm EDTForm 4
Jason B. ShandellPresident and General Counsel168,318—168,318Mar 1, 2019 · 8:01 pm ESTForm 4
Howard LeeDirector159,350—159,350Jun 3, 2026 · 9:20 pm EDTForm 4
Floyd F. PetersenDirector71,151—71,151Dec 4, 2018 · 9:01 pm ESTForm 4
Marilyn J. Purchaserelationship not stated43,26316,04459,307Jun 17, 2015 · 6:14 pm EDTForm 4
Yakob LiawatidewiSVP Corp Admin Center35,8836,36942,252Feb 14, 2019 · 6:30 pm ESTForm 4
Michael A ZasloffDirector37,667—37,667Jun 3, 2026 · 8:34 pm EDTForm 4
Diane G. GerstDirector31,899—31,899Jun 3, 2026 · 8:33 pm EDTForm 4
Stephen B. ShohetDirector30,706—30,706Dec 12, 2018 · 8:37 pm ESTForm 4
Richard K PrinsDirector29,625—29,625Aug 12, 2026 · 6:14 pm EDTForm 4
Gayle DeflinDirector19,057—19,057Jun 3, 2026 · 8:29 pm EDTForm 4
David Russell GaughDirector14,447—14,447Jun 3, 2026 · 8:31 pm EDTForm 4
Anthony T PierceDirector7,886—7,886Jul 13, 2026 · 7:38 pm EDTForm 4

Balances come from each insider’s most recent filing that reports a Table I holding; an insider who left the company years ago still appears with their last-known figure and its date. Indirect totals collapse multiple vehicles (trusts, LLCs) into one number — open the filing for the breakdown. Shares as filed, not split-adjusted.