Constantin Ionel Stefan Net Worth
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Constantin Ionel Stefan has an estimated net worth of at least $11.1 million*, as of Oct. 29, 2025. They own 723,330 shares of AMPX stock. They have sold 1.0 million shares of AMPX stock since 2021, for an estimated $547,331.
Constantin Ionel Stefan $AMPX SEC Form 4 Insider Trading
Constantin Ionel Stefan has filed a total of 16 insider trades in $AMPX since 2021. Their most recent trade was a sale of 25,366 shares, made on Feb 23, 2026. Their largest trade was a sale of 492,827 shares, made on Jan 22, 2026. We estimate that they now own 723,330 shares of $AMPX, worth an estimated $10.5 million.
Insider Trading at $AMPX
There have been a total of 98 insider trades reported at $AMPX since 2021, with 0 shares purchased and 8.0 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 61,251 shares reported by Kang Sun (None), made on Feb 23, 2026.
History of Insider Stock Trades by Constantin Ionel Stefan
| Company Ticker | Purchase / Sale | Shares | Date | Disclosed (EST) |
|---|---|---|---|---|
AMPX
|
Sale | 25,366 | Feb 23, 2026 | Feb. 24, 2026, 6:08 p.m. |
|
AMPX
|
Sale | 39,690 | Jan 28, 2026 | Jan. 30, 2026, 7:02 p.m. |
|
AMPX
|
Sale | 492,827 | Jan 22, 2026 | Jan. 23, 2026, 6:36 p.m. |
|
AMPX
|
Sale | 1,600 | Jan 23, 2026 | Jan. 23, 2026, 6:36 p.m. |
|
AMPX
|
Sale | 73,280 | Jan 21, 2026 | Jan. 23, 2026, 6:36 p.m. |
|
AMPX
|
Sale | 198,255 | Dec 11, 2025 | Dec. 15, 2025, 7:25 p.m. |
|
AMPX
|
Sale | 25,024 | Nov 21, 2025 | Nov. 25, 2025, 7:55 p.m. |
|
AMPX
|
Sale | 19,159 | Aug 21, 2025 | Aug. 25, 2025, 8:04 p.m. |
|
AMPX
|
Sale | 20,366 | May 21, 2025 | May 23, 2025, 5:54 p.m. |
|
AMPX
|
Sale | 9,066 | Feb 21, 2025 | Feb. 24, 2025, 8:38 p.m. |
|
AMPX
|
Sale | 8,575 | Nov 21, 2024 | Nov. 22, 2024, 5:21 p.m. |
|
AMPX
|
Sale | 8,800 | Aug 21, 2024 | Aug. 22, 2024, 4:57 p.m. |
|
AMPX
|
Sale | 5,272 | May 21, 2024 | May 24, 2024, 9:08 p.m. |
|
AMPX
|
Sale | 4,121 | May 22, 2024 | May 24, 2024, 9:08 p.m. |
|
AMPX
|
Sale | 46,370 | Sep 14, 2023 | Sept. 18, 2023, 5:40 p.m. |
|
AMPX
|
Sale | 33,630 | Sep 15, 2023 | Sept. 18, 2023, 5:40 p.m. |
$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
-
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.