Insiders who reported open-market trades in the last 12 months at the companies Jack Y. Zhang files at. Multiple unrelated insiders buying the same stock within a short window, cluster buying, has historically been one of the strongest Form 4 signals.
Floyd F. Petersen - $454K in AMPH purchases and sales in the last 12 months
Rong Zhou - $315K in AMPH purchases and sales in the last 12 months
William J. Peters - $287K in AMPH purchases and sales in the last 12 months
Richard K. Prins - $275K in AMPH purchases and sales in the last 12 months
More insiders (A-Z)
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Jack Y. Zhang is a corporate insider, tracked as CEO & CHIEF SCIENTIFIC OFFICER of Amphastar Pharmaceuticals, Inc. (AMPH). InsiderAlpha holds 6 primary Form 4 filings for them, the earliest from 2024, updated as new SEC EDGAR filings are processed.
When did Jack Y. Zhang last file a Form 4?
The most recent primary Form 4 on record is dated 17 March 2026, one of 6 filings going back to 2024.
Jack Y. Zhang is CEO & CHIEF SCIENTIFIC OFFICER of Amphastar Pharmaceuticals, Inc. (AMPH). 6 SEC Form 4 filings on record going back to 2024, most recently on 17 March 2026.
Recent transactions
13
The latest 13 SEC Form 4 transactions reported by Jack Y. Zhang.
InsiderAlpha's records for Jack Y. Zhang go back to 2024: 6 primary Form 4 filings, an average of 2.0 per year. No recorded transaction carries a Rule 10b5-1 plan flag. An absent flag does not establish whether a transaction was pre-arranged or discretionary.
