Fumihide Esaka

CIK 2078454 · Chief Executive Officer · last filed 2026-10-06

Fumihide Esaka is a Chief Executive Officer who has filed 15 SEC Form 4 insider transactions across 1 company since 2025. The most recent filing shows the insider sold $1.2M of AMBQ on Oct 6, 2026. Across all open-market trades the lifetime net is −$16.4M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $22.6M 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

$22.61M

Companies

Total Filings

Lifetime Open-Market Net

-$16.38M

Charts

Trading activity, where the exposure sits, and each trade against the stock price.

AMBQ price and trades

Daily close with each Form 4 filing on this company marked: green = open-market buy, red = open-market sale, purple = grants, exercises, gifts and other non-market transactions. Marker size scales with the dollar value.

Shares held

Shares owned after each reported transaction on this company (direct holdings as reported).

Open-market buying and selling

by month

Dollar value of open-market purchases (code P, up) and sales (code S, down) across all companies, by filing month. Grants, exercises and gifts are excluded.

Exposure by company

latest

OfficerDirector10% owner* stale (no filing in 3 yrs)

Most recently reported shares × current price. Faded bars (*) have had no filing in 3 years, so the person may no longer hold them. Click a bar to chart that company.

Filer Profile

Reported Address

C/O AMBIQ MICRO, INC.
6500 RIVER PLACE BLVD BUILDING 7 STE 200
AUSTIN, TX 78730

Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

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	453,347	$49.88	$22.61M	-$16.38M	9	2026-10-06

Recent Filings

15 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
2026-10-06	AMBQ	Sell (S)	−16,560	-$1.15M	EDGAR
2026-10-02	AMBQ	Notice (144)	−16,560	-$1.15M	EDGAR
2026-09-15	AMBQ	Mixed	—	-$3.24M	EDGAR
2026-09-11	AMBQ	Notice (144)	−50,000	-$3.17M	EDGAR
2026-09-02	AMBQ	Mixed	+9,271	-$4.75M	EDGAR
2026-09-01	AMBQ	Notice (144)	−48,973	-$2.76M	EDGAR
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

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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.