AMPH insider trading — Amphastar Pharmaceuticals, Inc.
Over the last 90 days, insiders at Amphastar Pharmaceuticals, Inc. (AMPH) made 0 open-market purchases worth $0 and 3 open-market sales worth $477K, making them net sellers by $477K. The largest sale was by Zhou Rong (SENIOR EVP, PRODUCTION CENTER), who sold 10,000 shares for $239K on Sep 16, 2026.
Updated Oct 16, 2026.
Recent AMPH insider transactions
Every Form 4 filed by Amphastar Pharmaceuticals, Inc. officers, directors and 10% owners in the last 90 days, newest first. P = open-market purchase, S = open-market sale; other codes are awards, option exercises, tax withholding or gifts.
| Trade date | Insider | Role | Type | Ownership | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|---|
| Sep 21, 2026 | Peters William J | CFO, EVP & TREASURER | S · Sale · 10b5-1 | Direct | 4,139 | $25.00 | $103K | Form 4 |
| Sep 16, 2026 | Zhou Rong | SENIOR EVP, PRODUCTION CENTER | M · Option exercise | Direct | 10,000 | $13.35 | $134K | Form 4 |
| Sep 16, 2026 | Zhou Rong | SENIOR EVP, PRODUCTION CENTER | S · Sale | Direct | 10,000 | $23.94 | $239K | Form 4 |
| Sep 2, 2026 | Zhou Rong | SENIOR EVP, PRODUCTION CENTER | S · Sale | Direct | 3,187 | $23.63 | $75K | Form 4 |
| Aug 11, 2026 | Prins Richard K | Director | S · Sale | Direct | 7,973 | $20.30 | $162K | Form 4 |
| Aug 7, 2026 | Peters William J | CFO, EVP & TREASURER | M · Option exercise · 10b5-1 | Direct | 5,053 | $19.79 | $100K | Form 4 |
| Aug 7, 2026 | Peters William J | CFO, EVP & TREASURER | S · Sale · 10b5-1 | Direct | 8,180 | $22.48 | $184K | Form 4 |
AMPH insider trading FAQ
Are insiders buying AMPH stock?
Not on the open market. In the last 90 days, Amphastar Pharmaceuticals, Inc. insiders made no open-market purchases, and 3 open-market sales totaling $477K. Purchases with the insider's own money are generally seen as a stronger signal than sales, which happen for many reasons (taxes, diversification, planned 10b5-1 sales).
Who are the insiders trading AMPH?
Recent sellers: Prins Richard K, Zhou Rong.
Where does AMPH insider trading data come from?
Every transaction comes from SEC Form 4 filings on EDGAR. Company officers, directors and 10% owners must file a Form 4 within two business days of buying or selling. InsiderBolt reads these filings directly from the SEC.
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Insider trading data is for informational purposes only and is not investment advice. Filings can be amended; always confirm details on SEC EDGAR.