Insider · CIK 0002067233
Thomas M Stepien
Files at AMPX (Amprius Technologies, Inc.). First filing May 26, 2026, latest Aug 25, 2026.
In brief
Thomas M Stepien files SEC Form 4 as president, director and CEO at AMPX (Amprius Technologies, Inc.). Since May 26, 2026, Thomas M Stepien has reported 0 open-market buys worth $0 and 4 open-market sells worth $1.3M, the latest filed on Aug 25, 2026.
A track record needs three past buys with six months of prices behind them; Thomas M Stepien has 0, so none is measured yet.
The newest scored trade: sold $324k of AMPX on Aug 21, 2026, filed Aug 25, 2026, scored 54 (moderate). In the last 12 months: 0 buys worth $0 and 4 sells worth $1.3M.
Where the trades landed
Last year at the company this insider has traded most, with each buy and sell on the bar it happened.
AMPX: Amprius Technologies, Inc.
Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value. Click a marked bar to open the signal.Charts by TradingView Lightweight Charts™
Signals
This insider’s open-market buys and sells, scored.
| Score | Company | Value | Holdings | Price context | Filed |
|---|---|---|---|---|---|
| 54Moderate | Amprius Technologies, Inc. | $324k 31,529 shares | -5% | +52% from low-55% from high | |
| 46Moderate | Amprius Technologies, Inc. | $42k 2,000 shares | -0% | +757% from low-2% from high | |
| 48Moderate | Amprius Technologies, Inc. | $75k 4,375 shares | -1% | +552% from low-24% from high | |
| 64Notable | Amprius Technologies, Inc. | $898k 60,702 shares | -8% | +532% from low-33% from high |
Planned sales
Form 144 notices this insider filed before selling restricted or control stock, newest first.
| Filed | Company | Shares | Value | Sale date | Past 3 months |
|---|---|---|---|---|---|
| Aug 25, 2026 | AMPX AMPRIUS TECHNOLOGIES, INC. | 23,529 0.02% of outstanding | $243k | Aug 21, 2026 | $197k |
| Aug 24, 2026 | AMPX AMPRIUS TECHNOLOGIES, INC. | 8,000 0.01% of outstanding | $80k | Aug 24, 2026 | $360k |
| Jun 4, 2026 | AMPX AMPRIUS TECHNOLOGIES, INC. | 2,000 0.00% of outstanding | $42k | Jun 4, 2026 | $973k |
| May 28, 2026 | AMPX AMPRIUS TECHNOLOGIES, INC | 4,375 0.00% of outstanding | $75k | May 27, 2026 | $898k |
| May 26, 2026 | AMPX AMPRIUS TECHNOLOGIES, INC | 60,702 0.04% of outstanding | $898k | May 21, 2026 | none |
Transactions
Every row this insider has filed, 17 in all, newest first.
| Date | Company | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|---|
| Aug 21, 2026 | AMPX Amprius Technologies, Inc. | SOpen-market sale Common stock | -23,529 | $10.34 | $243k | 602,096 | Aug 25, 2026 |
| Aug 24, 2026 | AMPX Amprius Technologies, Inc. | SOpen-market sale Common stock | -8,000 | $10.03 | $80k | 594,096 | Aug 25, 2026 |
| Aug 25, 2026 | AMPX Amprius Technologies, Inc. | GGift Common stock | -5,000 | $0.00 | $0 | 589,096 | Aug 25, 2026 |
| Aug 25, 2026 | AMPX Amprius Technologies, Inc. | GGift Common stock | -5,000 | $0.00 | $0 | 584,096 | Aug 25, 2026 |
| Aug 25, 2026 | AMPX Amprius Technologies, Inc. | GGift Common stock | -5,000 | $0.00 | $0 | 579,096 | Aug 25, 2026 |
| Aug 25, 2026 | AMPX Amprius Technologies, Inc. | GGift Common stock | -346 | $0.00 | $0 | 578,750 | Aug 25, 2026 |
| Aug 25, 2026 | AMPX Amprius Technologies, Inc. | AGrant or award Common stockindirect: See Footnote | +346 | $0.00 | $0 | 37,260 | Aug 25, 2026 |
| Jun 4, 2026 | AMPX Amprius Technologies, Inc. | GGift Common stock | -30,384 | $0.00 | $0 | 664,539 | Jun 5, 2026 |
| Jun 4, 2026 | AMPX Amprius Technologies, Inc. | GGift Common stock | -36,914 | $0.00 | $0 | 627,625 | Jun 5, 2026 |
| Jun 4, 2026 | AMPX Amprius Technologies, Inc. | GGift Common stockindirect: See Footnote | +36,914 | $0.00 | $0 | 36,914 | Jun 5, 2026 |
| Jun 4, 2026 | AMPX Amprius Technologies, Inc. | SOpen-market sale Common stock | -2,000 | $20.97 | $42k | 625,625 | Jun 5, 2026 |
| May 27, 2026 | AMPX Amprius Technologies, Inc. | SOpen-market sale Common stock | -4,375 | $17.19 | $75k | 694,923 | May 28, 2026 |
| May 21, 2026 | AMPX Amprius Technologies, Inc. | SOpen-market sale Common stock | -60,702 | $14.79 | $898k | 699,298 | May 26, 2026 |
| Dec 19, 2025 | AMPX Amprius Technologies, Inc. | AGrant or award Common stock | +200,000 | $0.00 | $0 | 760,000 | May 7, 2026 |
| Mar 4, 2026 | AMPX Amprius Technologies, Inc. | AGrant or award Common stock | +150,000 | $0.00 | $0 | 760,000 | Mar 6, 2026 |
| Dec 19, 2025 | AMPX Amprius Technologies, Inc. | AGrant or award Common stock | +200,000 | $0.00 | $0 | 610,000 | Dec 22, 2025 |
| May 1, 2025 | AMPX Amprius Technologies, Inc. | AGrant or award Common stock | +400,000 | $0.00 | $0 | 400,000 | May 6, 2025 |
Questions about Thomas M Stepien
Answered from the filings on this page, as of the latest one.
Is Thomas M Stepien buying or selling?
In the last 12 months Thomas M Stepien reported 0 open-market buys worth $0 and 4 open-market sells worth $1.3M on SEC Form 4; the latest was sold $324k of AMPX on Aug 21, 2026. Grants, option exercises and tax withholding are not counted.
How did Thomas M Stepien's past buys perform?
Not measured yet. InsiderTell needs three past buys with six months of prices to publish a track record, and Thomas M Stepien has 0.
Where does Thomas M Stepien file Form 4?
Thomas M Stepien has filed Form 4 at AMPX (Amprius Technologies, Inc.) as Chief Executive Officer. A Form 4 is required of officers, directors and holders of more than 10% of a share class within two business days of a trade.
Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.