Rong Zhou is VP at Amphastar Pharmaceuticals, Inc. (AMPH). They have made 27 open-market trades across 1 company since 2015, most recently 2026-09-16.
CIK 0001645326
Unrated. We grade insiders only on stock they chose to buy on the open market. Grants, option exercises and vesting say nothing about timing, so they don't count — which is why someone can file often and still have no grade. It isn't a bad sign: unrated buys beat every graded tier below A.
0 open-market purchases, against 27 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| AMPH | 169,203 | $4.4M |
Shares reported on the most recent Form 4, priced at the 2026-09-17 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| AMPH | SELL | 2026-09-16 | 2026-09-17 | $23.94 | $239K | +13.0% | — | — |
| AMPH | SELL | 2025-12-17 | 2025-12-18 | $26.20 | $513K | +1.4% | -1.7% | -28.0% |
| AMPH | SELL | 2024-12-12 | 2024-12-16 | $44.86 | $673K | -6.5% | -10.4% | -31.5% |
| AMPH | SELL | 2024-11-12 | 2024-11-13 | $48.88 | $674K | -1.8% | -7.1% | -29.2% |
| AMPH | SELL | 2024-09-13 | 2024-09-17 | $48.26 | $145K | -1.2% | +2.3% | -15.9% |
| AMPH | SELL | 2024-08-26 | 2024-08-27 | $48.35 | $193K | -7.4% | -0.5% | -7.2% |
| AMPH | SELL | 2023-12-01 | 2023-12-05 | $59.03 | $924K | -2.8% | +8.9% | -19.9% |
| AMPH | SELL | 2023-06-15 | 2023-06-20 | $51.79 | $259K | +3.0% | +13.4% | -17.1% |
| AMPH | SELL | 2023-06-13 | 2023-06-14 | $48.24 | $241K | +15.9% | +15.4% | -3.7% |
| AMPH | SELL | 2023-05-18 | 2023-05-19 | $44.21 | $442K | +2.1% | +26.3% | +20.0% |
| AMPH | SELL | 2022-02-25 | 2022-03-01 | $28.77 | $762K | +24.7% | +30.5% | +35.1% |
| AMPH | SELL | 2022-02-08 | 2022-02-09 | $26.77 | $187K | +0.8% | +32.4% | +31.3% |
| AMPH | SELL | 2022-01-10 | 2022-01-11 | $25.36 | $1.1M | -2.1% | +4.3% | +63.4% |
| AMPH | SELL | 2021-11-11 | 2021-11-12 | $21.67 | $339K | -2.2% | +0.2% | +23.1% |
| AMPH | SELL | 2021-08-02 | 2021-08-04 | $21.24 | $388K | -6.4% | -6.7% | -6.9% |
| AMPH | SELL | 2021-07-26 | 2021-07-27 | $20.87 | $125K | -2.4% | -9.1% | -8.2% |
| AMPH | SELL | 2021-07-20 | 2021-07-22 | $20.57 | $213K | +4.9% | -6.4% | -5.0% |
| AMPH | SELL | 2021-06-08 | 2021-06-10 | $19.43 | $502K | +2.7% | +1.9% | -4.8% |
| AMPH | SELL | 2021-05-13 | 2021-05-17 | $19.72 | $701K | -4.7% | +1.0% | -3.1% |
| AMPH | SELL | 2020-06-03 | 2020-06-05 | $18.98 | $872K | +2.1% | +12.1% | +2.3% |
| AMPH | SELL | 2019-05-06 | 2019-05-07 | $22.76 | $218K | -2.0% | -10.1% | -13.4% |
| AMPH | SELL | 2019-05-06 | 2019-05-07 | $22.76 | $218K | -2.0% | -10.1% | -13.4% |
| AMPH | SELL | 2019-03-01 | 2019-03-04 | $25.00 | $80K | -17.2% | -15.6% | -23.6% |
| AMPH | SELL | 2019-02-05 | 2019-02-07 | $23.00 | $99K | +8.6% | +4.7% | -0.7% |
| AMPH | SELL · 10b5-1 | 2018-12-03 | 2018-12-06 | $22.00 | $24K | -8.0% | -4.3% | +11.5% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.