Fumihide Esaka is CEO at Ambiq Micro, Inc. (AMBQ). They have made 1 open-market trade across 1 company since 2026, most recently 2026-09-02.
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 1 sale. Too few scored purchases to measure a record yet.
| Ticker | Shares | Value |
|---|---|---|
| AMBQ | 460,460 | $28.0M |
Shares reported on the most recent Form 4, priced at the 2026-09-15 close.
Counted per filing, not per execution lot — a purchase filled in several tranches is one decision.
Grouped by shared companies and similar filing behaviour. This is a similarity measure, not a ranking or a performance signal.