Diane G. Gerst is VP at Amphastar Pharmaceuticals, Inc. (AMPH). They have made 12 open-market trades across 1 company since 2015, most recently 2026-06-01.
CIK 0001611283
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 12 sales. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| AMPH | 31,899 | $894K |
Shares reported on the most recent Form 4, priced at the 2026-06-03 close.
| Ticker | Type | Traded | Filed | Price | Value | 7d Stock | 30d Stock | 90d Stock |
|---|---|---|---|---|---|---|---|---|
| AMPH | SELL | 2022-07-18 | 2022-07-19 | $37.23 | $113K | +2.7% | -10.9% | -19.5% |
| AMPH | SELL | 2022-07-11 | 2022-07-12 | $36.26 | $110K | +1.8% | -11.3% | -20.7% |
| AMPH | SELL | 2022-07-05 | 2022-07-06 | $35.00 | $63K | +3.5% | +3.6% | -19.5% |
| AMPH | SELL | 2022-06-30 | 2022-07-05 | $35.00 | $180K | +7.4% | +7.3% | -17.5% |
| AMPH | SELL · 10b5-1 | 2017-12-19 | 2017-12-19 | $19.48 | $10K | +0.4% | +1.9% | +2.5% |
| AMPH | SELL · 10b5-1 | 2017-12-12 | 2017-12-14 | $18.96 | $10K | +5.4% | +0.2% | +8.0% |
| AMPH | SELL · 10b5-1 | 2017-11-28 | 2017-11-30 | $18.15 | $9K | -1.7% | -2.2% | -6.3% |
| AMPH | SELL · 10b5-1 | 2017-11-21 | 2017-11-21 | $18.81 | $10K | +0.0% | +3.2% | -2.5% |
| AMPH | SELL · 10b5-1 | 2017-11-15 | 2017-11-17 | $17.77 | $9K | +7.6% | +7.3% | +4.6% |
| AMPH | SELL · 10b5-1 | 2017-11-07 | 2017-11-09 | $17.93 | $9K | +0.8% | -0.7% | -4.2% |
| AMPH | SELL · 10b5-1 | 2017-10-24 | 2017-10-26 | $18.29 | $10K | -3.2% | -2.4% | +4.5% |
| AMPH | SELL · 10b5-1 | 2017-10-17 | 2017-10-19 | $18.48 | $10K | -2.5% | -1.1% | +4.9% |
| AMPH | SELL | 2017-10-05 | 2017-10-06 | $18.87 | $319K | -2.4% | -5.4% | -3.8% |
| AMPH | SELL | 2016-12-15 | 2016-12-16 | $20.51 | $121K | -13.5% | -22.3% | -37.1% |
| AMPH | SELL | 2016-08-19 | 2016-08-19 | $19.28 | $464K | -2.6% | -2.6% | +10.5% |
| AMPH | SELL | 2016-08-19 | 2016-08-19 | $19.28 | $464K | -2.6% | -2.6% | +10.5% |
| AMPH | SELL | 2016-05-18 | 2016-05-19 | $13.97 | $20K | +10.8% | +3.5% | +32.8% |
| AMPH | SELL | 2016-04-19 | 2016-04-20 | $13.04 | $73K | -4.7% | +19.7% | +32.4% |
| AMPH | SELL | 2016-04-18 | 2016-04-20 | $12.83 | $201K | -4.7% | +19.7% | +32.4% |
| AMPH | SELL | 2016-04-18 | 2016-04-20 | $12.89 | $548K | -4.7% | +19.7% | +32.4% |
| AMPH | SELL · 10b5-1 | 2015-04-08 | 2015-04-10 | $15.79 | $158K | -12.7% | -2.5% | -2.5% |
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.