Constantin Ionel Stefan

CIK 1940928 · Chief Technology Officer · last filed 2026-05-28

Constantin Ionel Stefan is a Chief Technology Officer who has filed 23 SEC Form 4 insider transactions across 1 company since 2022. The most recent filing shows the insider sold $55.2K of AMPX.WS on May 28, 2026. Across all open-market trades the lifetime net is −$10.9M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $5.7M 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.

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Disclosed Exposure

$5.69M

Companies

1

Total Filings

23

Lifetime Open-Market Net

-$10.93M

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
AMPX.WS Chief Technology Officer 801,310 $7.10 $5.69M -$10.93M 22 2026-05-28

Recent Filings

23 filings
Form 4 transactions across all companies, newest first.
Filed Symbol Action Net Shares Net $ Link
2026-05-28 AMPX.WS Sell (S) −3,208 -$55.2K EDGAR
2026-05-26 AMPX.WS Sell (S) −28,812 -$426.1K EDGAR
2026-03-06 AMPX.WS Grant (A) +110,000 $0 EDGAR
2026-02-24 AMPX.WS Sell (S) −25,366 -$257.6K EDGAR
2026-01-30 AMPX.WS Mixed -$474.3K EDGAR
2026-01-23 AMPX.WS Mixed -$6.75M EDGAR
2025-12-15 AMPX.WS Mixed −73,255 -$2.08M EDGAR
2025-11-25 AMPX.WS Sell (S) −25,024 -$252.3K EDGAR
2025-08-25 AMPX.WS Sell (S) −19,159 -$130.6K EDGAR
2025-05-23 AMPX.WS Sell (S) −20,366 -$49.5K EDGAR
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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.