Fumihide Esaka

CIK 2078454 · Chief Executive Officer · last filed 2026-08-18

Fumihide Esaka is a Chief Executive Officer who has filed 9 SEC Form 4 insider transactions across 1 company since 2025. The most recent filing, for AMBQ, was dated Aug 31, 2026. Across all open-market trades the lifetime net is −$5.1M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $25.3M across reported positions.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

Disclosed Exposure

$25.32M

Companies

1

Total Filings

9

Lifetime Open-Market Net

-$5.07M

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.

Symbol	Role	Shares	Price	Disclosed Exposure	Lifetime OM Net	Filings	Latest Filed
AMBQ	Chief Executive Officer	452,689	$55.94	$25.32M	-$5.07M	6	2026-08-18

Recent Filings

9 filings

Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.

Filed	Symbol	Action	Net Shares	Net $	Link
2026-08-31	AMBQ	Notice (144)	−35,000	-$2.01M	EDGAR
2026-08-18	AMBQ	Mixed	—	-$759.6K	EDGAR
2026-08-14	AMBQ	Notice (144)	−45,500	-$2.93M	EDGAR
2026-05-18	AMBQ	Mixed	+60,000	-$3.16M	EDGAR
2026-05-14	AMBQ	Notice (144)	−60,000	-$4.20M	EDGAR
2026-04-02	AMBQ	Grant (A)	+160,616	$0	EDGAR
2026-03-10	AMBQ	Grant (A)	+160,616	$0	EDGAR
2026-02-10	AMBQ	Exer (M)	+53,660	$315.5K	EDGAR
2025-10-06	AMBQ	Grant (A)	+159,907	$0	EDGAR

Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.