Constantin Ionel Stefan $AMPX SEC Form 4 Insider Trading

Constantin Ionel Stefan has filed a total of 18 insider trades in $AMPX since 2021. Their most recent trade was a sale of 3,208 shares, made on May 27, 2026. Their largest trade was a sale of 492,827 shares, made on Jan 22, 2026. We estimate that they now own 801,310 shares of $AMPX, worth an estimated $18.6 million.

Insider Trading at $AMPX

There have been a total of 116 insider trades reported at $AMPX since 2021, with 0 shares purchased and 10.7 million shares sold. The most active insider traders in $AMPX stock have been Jonathan Bornstein, Constantin Ionel Stefan, and Kang Sun. The most recent trade was a sale of 2,000 shares reported by Thomas M Stepien (Chief Executive Officer), made on Jun 04, 2026.

$AMPX Executives and Stock Owners with Insider Trades

• Jonathan Bornstein, President of Amprius Lab

• Constantin Ionel Stefan, Chief Technology Officer

• Kang Sun, Chief Executive Officer

• Sandra Wallach, Chief Financial Officer

• Thomas M Stepien, Chief Executive Officer

• Kang Sun, See Remarks

*This is only based off of information found in SEC filings, and may not reflect actual net worth. There may also be inaccuracies due to privately holdings filing errors, parsing errors, accidental double-counting of shares, incorrect classification of indirectly owned shares, sales prior to dataset start date, or any other number of issues.