Form4.ai tracks every SEC insider trade in real time. See every AMPX insider filing with a free account — no card.
See every AMPX insider filing — free account, no card.
Free accountAmprius Technologies, Inc. (AMPX) has 3 SEC Form 4 insider filings on record in the last 90 days. No insider purchases were filed — 3 sales totalling $1.3M. Most recent filing: Aug. 25, 2026.
Open-market value, last 90 days
Form 4 filings by type, last 90 days
| Date | Insider | Trade | Value | Price since buy |
|---|---|---|---|---|
| Aug 25, 2026 SEC filing | Stefan Constantin Ionel Chief Technology Officer | Sold | $306,931 | — |
| Aug 25, 2026 SEC filing | Sun Kang Director | Sold | $642,186 | — |
| Aug 25, 2026 SEC filing | Stepien Thomas M Chief Executive Officer | Sold | $321,165 | — |
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Form 4 is the filing company officers, directors and 10% shareholders must submit to the SEC within two business days of trading their own company's stock. Open-market purchases generally carry more signal than sales, which are often scheduled in advance. More on how this works.