Ownership & Insider Lab
Amphastar Pharmaceuticals, Inc. (AMPH)
Nasdaq · SEC CIK 0001297184
This is the supported SEC-traceable subset, not total insider ownership or personal wealth. Values reflect the current disclosed positions Grizzly Bulls can resolve and value. Latest source filing: Sep 17, 2026 · values through Sep 25, 2026.
Covered reporting owners
Filter the reporting-owner snapshot by holder, role, or security. Position values are shown only where the current reviewed data supports them.
| Holder | Role | Position | Current value | Latest filing |
|---|---|---|---|---|
| Rong Zhou | SENIOR EVP, PRODUCTION CENTER | 169,203 sharesCommon Stock, par value $0.0001 per share | $4.42M | Sep 17, 2026 |
| Richard K. Prins | Director | 29,625 sharesCommon Stock, par value $0.0001 per share | $774.1K | Aug 12, 2026 |
Recent supported insider transactions
These are supported direct, non-derivative historical transactions from companies where recent transaction history has passed separate review. Reported price is shown when present. The lab does not calculate gross proceeds and does not treat historical transactions as current wealth.
| Date | Holder | Action | Security | Units | Reported price | Filing |
|---|---|---|---|---|---|---|
| Sep 16, 2026 | Rong Zhou | SaleSEC code S | Common Stock, par value $0.0001 per share | 10,000 shares | $23.9404 | 4 |
| Sep 16, 2026 | Rong Zhou | AcquisitionSEC code M | Common Stock, par value $0.0001 per share | 10,000 shares | $13.35 | 4 |
| Sep 2, 2026 | Rong Zhou | SaleSEC code S | Common Stock, par value $0.0001 per share | 3,187 shares | $23.6291 | 4 |
| Aug 11, 2026 | Richard K. Prins | SaleSEC code S | Common Stock, par value $0.0001 per share | 7,973 shares | $20.3 | 4 |
| Jun 17, 2015 | Rong Zhou | SaleSEC code S | Common Stock, par value $0.0001 per share | 1,000 shares | $16.48 | 4 |
| Jun 15, 2015 | Rong Zhou | AcquisitionSEC code A | Common Stock, par value $0.0001 per share | 1,544 shares | $0 | 4 |
| May 27, 2015 | Richard K. Prins | AcquisitionSEC code A | Common Stock, par value $0.0001 per share | 8,686 shares | $0 | 4 |
| May 22, 2015 | Richard K. Prins | SaleSEC code S | Common Stock, par value $0.0001 per share | 1,942 shares | $14.755 | 4 |
| May 22, 2015 | Richard K. Prins | AcquisitionSEC code M | Common Stock, par value $0.0001 per share | 1,942 shares | $10.77 | 4 |
| May 21, 2015 | Richard K. Prins | SaleSEC code S | Common Stock, par value $0.0001 per share | 13,565 shares | $14.757 | 4 |
| May 21, 2015 | Richard K. Prins | DispositionSEC code M | Common Stock, par value $0.0001 per share | 1,664 shares | $10.77 | 4 |
| May 21, 2015 | Richard K. Prins | AcquisitionSEC code M | Common Stock, par value $0.0001 per share | 11,901 shares | $11.68 | 4 |
Published 12 of 17 source candidates under the current reviewed security-resolution rules.
Covered securities
| Security | Instrument family | Covered positions | Covered value |
|---|---|---|---|
| Common Stock, par value $0.0001 per share | ordinary-share | 2 | $5.2M |
Coverage and interpretation
Current holdings: direct positions that the reviewed ownership data can trace to an exact reporting owner, legal security, and current-basis quantity.
Current value: the existing published company-position valuation. This lab does not recalculate security values or infer missing positions.
Transactions: historical flow observations only. They are not used to reconstruct current ownership and are shown only for companies where recent transaction history is currently published.
Not included here: a claim of total insider ownership, total personal wealth, institutional 13F ownership, or an investment recommendation.