AMPX · Insider Trading
Amprius Technologies, Inc.
Every open-market purchase and sale reported by AMPX officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.
| Filed | Insider | Role | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-08-25 | Kang Sun | Director | Sell | −62,101 | −$642.19K |
| 2026-08-25 | Constantin Ionel Stefan | Chief Technology Officer | Sell | −29,681 | −$306.93K |
| 2026-08-25 | Thomas M Stepien | Chief Executive Officer | MIXED | −46,529 | −$323.55K |
| 2007-07-25 | Charles W. Dyke | Director | A | +1,000 | — |
| 2007-07-02 | Joel D Talcott | Vice President | A | +5,000 | — |
| 2007-07-02 | Ramon C H Venema | VP, Asst Treasurer, Asst Sec. | A | +3,000 | — |
| 2007-07-02 | Robert L Atchison | Vice President | A | +5,000 | — |
| 2007-07-02 | Sharon M Genberg | Vice President | A | +3,000 | — |
| 2007-05-22 | Douglas T McClure Jr | Director | A | +1,000 | — |
| 2007-05-22 | Alain C Briancon | Director | A | +1,000 | — |
| 2007-05-22 | Ramon C H Venema | VP, Asst Treasurer, Asst Sec. | A | +3,000 | — |
| 2007-05-22 | Sharon M Genberg | Vice President | A | +3,000 | — |
| 2007-05-22 | Peter Slusser | Director | A | +1,000 | — |
| 2007-05-22 | Joel D Talcott | Vice President | A | +5,000 | — |
| 2007-05-22 | Robert L Atchison | Vice President | A | +5,000 | — |
| 2007-05-22 | Ned S Goldstein | Director | A | +1,000 | — |
| 2007-04-06 | Sharon M Genberg | Vice President | M | +3,000 | +$3.45K |
| 2007-04-06 | Ramon C H Venema | VP, Asst Treasurer, Asst Sec. | M | +1,500 | +$1.72K |
| 2007-04-05 | Craig L McKibben | Vice Pres., Treasurer & CFO | MIXED | — | −$130.29K |
| 2007-04-05 | Joel D Talcott | Vice President | MIXED | — | −$83.11K |
| 2007-03-12 | Joel D Talcott | Vice President | MIXED | — | −$20.39K |
| 2007-03-12 | Craig L McKibben | Vice Pres., Treasurer & CFO | MIXED | — | −$80.44K |
| 2007-03-08 | Joel D Talcott | Vice President | MIXED | — | −$56.86K |
| 2007-02-21 | D Gordon Strickland | CEO, President & Director | A | +25,000 deriv. | — |
| 2007-02-15 | Craig L McKibben | Vice Pres., Treasurer & CFO | MIXED | — | −$59.46K |
| 2007-02-15 | Craig L McKibben | Vice Pres., Treasurer & CFO | MIXED | — | −$13.65K |
| 2007-02-09 | Craig L McKibben | Vice Pres., Treasurer & CFO | MIXED | — | −$59.46K |
| 2007-02-06 | Joel D Talcott | Vice President | MIXED | — | −$74.29K |
| 2007-01-16 | Craig L McKibben | Vice Pres., Treasurer & CFO | MIXED | — | −$95.07K |
| 2007-01-09 | Joel D Talcott | Vice President | MIXED | — | −$83.15K |
| 2007-01-08 | Craig L McKibben | Vice Pres., Treasurer & CFO | MIXED | — | −$95.07K |
| Insider | Role | Shares Held | Value |
|---|---|---|---|
| Kang Sun | Director | 1,274,803 | $9.83M |
| Constantin Ionel Stefan | Chief Technology Officer | 771,629 | $5.95M |
| Thomas M Stepien | Chief Executive Officer | 631,356 | $4.87M |
Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.
Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.
Full filing history and per-insider positions are on the AMPX quote page; the site-wide leaderboard is on the insider transactions hub.
Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.