Summary
Updated Aug 31, 2026
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
13Every recent SEC Form 4 transaction Jack Y. Zhang has reported, most recent first.
Trading Pattern
InsiderAlpha's records for Jack Y. Zhang go back to 2024: 6 primary Form 4 filings, an average of 2.0 per year. No transaction on record carries a Rule 10b5-1 flag - the filings look discretionary rather than pre-scheduled, which makes their timing more informative as a signal.
Other Insiders Active in the Same Stocks
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 - $484K of AMPH open-market activity in the last 12 months
- Richard K. Prins - $275K of AMPH open-market activity in the last 12 months
- William J. Peters - $184K of AMPH open-market activity in the last 12 months
More Notable Insiders
Other corporate insiders with significant SEC Form 4 track records on InsiderAlpha:
Frequently Asked Questions
Who is Jack Y. Zhang?
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.
Where can I see all of Jack Y. Zhang's SEC filings?
All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.
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