Amprius Technologies, Inc. (AMPX)
Data as of , from SEC Form 4 filings.
Net insider selling (90d)Watch AMPX
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Kang Sun - DirectorOpen-market sale$642K
About Amprius Technologies, Inc. (AMPX)
Amprius Technologies, Inc. is an SEC registrant, filing under CIK 0001899287, classified as miscellaneous electrical machinery, equipment and supplies. It is grouped with Information Technology companies on this site.
AMPX Form 4 activity by transaction type, last 90 days
| Form 4 transaction type | Transactions | Shares | Total value |
|---|---|---|---|
| Open-market sale | 4 | 123,311 | $1.27M |
| Grant or award | 1 | 346 | |
| Bona-fide gift | 4 | 15,346 |
Dollar totals cover purchases and sales only (codes P and S). Grants, option exercises, gifts and tax withholding are counted in shares, because none of them is a trade at a market price.
AMPX insider transactions (Form 4)
7851 Form 4 filings on record, the earliest from Oct 25, 2024, newest first. Filing history page 1 of 2.
| Date | Insider | Transaction | Security | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Kang Sun - Director | Open-market sale | Common stock | 62,101 | $10.34 footnote F2 | $642K | |
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| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 29,681 | $10.34 footnote F2 | $307K | |
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| Thomas M. Stepien - Officer | Open-market sale | Common stock | 23,529 | $10.34 footnote F2 | $243K | |
| Thomas M. Stepien - Officer | Open-market sale | Common stock | 8,000 | $10.03 | $80K | |
| Thomas M. Stepien - Officer | Gift | Common stock | 5,000 footnote F4 | $0.00 | - | |
| Thomas M. Stepien - Officer | Gift | Common stock | 5,000 footnote F4 | $0.00 | - | |
| Thomas M. Stepien - Officer | Gift | Common stock | 5,000 footnote F4 | $0.00 | - | |
| Thomas M. Stepien - Officer | Gift | Common stock | 346 footnote F5 | $0.00 | - | |
| Thomas M. Stepien - Officer | Grant or award | Common stock | 346 footnote F5 | $0.00 | - | |
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| Kathleen A. Bayless - Director | Grant or award | Common stock | 10,423 footnote F1 | $0.00 | - | |
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 Livingston Satterthwaite - Director | Grant or award | Common stock | 10,423 footnote F1 | $0.00 | - | |
| ||||||
| Donald R. Dixon - Director | Grant or award | Common stock | 10,423 footnote F1 | $0.00 | - | |
| Donald R. Dixon - Director | Open-market sale | Common stock | 85,000 | $17.17 | $1.46M | |
| ||||||
| Steven Chu - Director | Grant or award | Common stock | 10,423 footnote F1 | $0.00 | - | |
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| Donald R. Dixon - Director | Open-market sale | Common stock | 40,000 | $19.13 | $765K | |
| Thomas M. Stepien - Officer | Gift | Common stock | 30,384 footnote F1 | $0.00 | - | |
| Thomas M. Stepien - Officer | Gift | Common stock | 36,914 footnote F3 | $0.00 | - | |
| Thomas M. Stepien - Officer | Gift | Common stock | 36,914 footnote F3 | $0.00 | - | |
| Thomas M. Stepien - Officer | Open-market sale | Common stock | 2,000 | $20.97 | $42K | |
| ||||||
| Kang Sun - Director | Open-market sale | Common stock | 356 | $17.19 footnote F2 | $6K | |
| ||||||
| Thomas M. Stepien - Officer | Open-market sale | Common stock | 4,375 | $17.19 footnote F2 | $75K | |
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| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 3,208 | $17.19 footnote F2 | $55K | |
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| Donald R. Dixon - Director | Open-market sale | Common stock | 17,895 | $17.90 | $320K | |
| Kang Sun - Director | Open-market sale | Common stock | 67,796 | $14.79 footnote F2 | $1.00M | |
| ||||||
| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 28,812 | $14.79 footnote F2 | $426K | |
| ||||||
| Thomas M. Stepien - Officer | Open-market sale | Common stock | 60,702 | $14.79 footnote F2 | $898K | |
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| Thomas M. Stepien - Officer | Grant or award | Common stock | 200,000 | $0.00 | - | |
| Kang Sun - Director | Grant or award | Common stock | 6,250 footnote F1 | $0.00 | - | |
| ||||||
| Kang Sun - Director | Option exercise | Common stock | 1,312,505 | $1.78 | $2.34M | |
| Kang Sun - Director | Option exercise | Common stock | 187,495 | $3.68 | $690K | |
| Kang Sun - Director | Open-market sale | Common stock | 1,250,963 | $15.73 footnote F3 | $19.68M | |
| Kang Sun - Director | Open-market sale | Common stock | 249,037 | $16.78 footnote F4 | $4.18M | |
| Kang Sun - Director | Option exercise | Stock Option (right to buy) | 1,312,505 | $1.78 | $2.34M | |
| Kang Sun - Director | Option exercise | Stock Option (right to buy) | 187,495 | $3.68 | $690K | |
| ||||||
| Kang Sun - Director | Open-market sale | Common stock | 152,823 | $18.69 footnote F2 | $2.86M | |
| Kang Sun - Director | Open-market sale | Common stock | 65,046 | $19.06 footnote F4 | $1.24M | |
| ||||||
 Ricardo C. Rodriguez - Officer | Grant or award | Common stock | 150,000 | $0.00 | - | |
 Wen Hsuan Hsieh - Director | Open-market sale | Common stock | 282,500 | $18.55 footnote F2 | $5.24M | |
| Wen Hsuan Hsieh - Director | Open-market sale | Common stock | 130,646 | $18.22 footnote F3 | $2.38M | |
| Wen Hsuan Hsieh - Director | Option exercise | Stock Option (right to buy) | 270,251 | $2.61 | $705K | |
| Wen Hsuan Hsieh - Director | Option exercise | Common stock | 270,251 | $2.61 | $705K | |
| ||||||
| Steven Chu - Director | Open-market sale | Common stock | 166,632 | $17.92 footnote F2 | $2.99M | |
| Steven Chu - Director | Option exercise | Common stock | 86,143 | $2.61 | $225K | |
| Steven Chu - Director | Option exercise | Common stock | 69,422 | $0.62 | $43K | |
| Steven Chu - Director | Open-market sale | Common stock | 100,000 | $18.65 footnote F3 | $1.86M | |
| Steven Chu - Director | Open-market sale | Common stock | 50,000 | $18.21 footnote F4 | $911K | |
| Steven Chu - Director | Open-market sale | Common stock | 5,565 | $18.53 footnote F5 | $103K | |
| Steven Chu - Director | Option exercise | Stock Option (right to buy) | 104,132 | $0.62 | $65K | |
| Steven Chu - Director | Option exercise | Stock Option (right to buy) | 86,143 | $2.61 | $225K | |
| Steven Chu - Director | Option exercise | Stock Option (right to buy) | 69,422 | $0.62 | $43K | |
| Steven Chu - Director | Option exercise | Common stock | 104,132 | $0.62 | $65K | |
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| Ricardo C. Rodriguez - Officer | Grant or award | Common stock | 150,000 footnote F1 | $0.00 | - | |
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| Thomas M. Stepien - Officer | Grant or award | Common stock | 150,000 footnote F1 | $0.00 | - | |
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| Constantin Ionel Stefan - Officer | Grant or award | Common stock | 110,000 footnote F1 | $0.00 | - | |
| ||||||
| Kang Sun - Director | Open-market sale | Common stock | 61,251 | $10.16 footnote F2 | $622K | |
| ||||||
| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 25,366 | $10.16 footnote F2 | $258K | |
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| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 90 | $0.62 | $56 | |
| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 39,600 | $0.05 | $2K | |
| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 39,690 | $12.00 footnote F3 | $476K | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 90 | $0.00 | - | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 39,600 | $0.00 | - | |
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| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 41,563 | $0.62 | $26K | |
| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 15,834 | $0.05 | $792 | |
| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 15,883 | $0.05 | $794 | |
| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 73,280 | $12.00 footnote F3 | $879K | |
| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 253,928 | $0.05 | $13K | |
| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 72,795 | $0.45 | $33K | |
| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 166,104 | $0.05 | $8K | |
| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 492,827 | $12.04 footnote F4 | $5.93M | |
| Constantin Ionel Stefan - Officer | Option exercise | Common stock | 1,600 | $0.05 | $80 | |
| Constantin Ionel Stefan - Officer | Open-market sale | Common stock | 1,600 | $12.00 footnote F5 | $19K | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 41,563 | $0.00 | - | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 15,834 | $0.00 | - | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 15,883 | $0.00 | - | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 253,928 | $0.00 | - | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 72,795 | $0.00 | - | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 166,104 | $0.00 | - | |
| Constantin Ionel Stefan - Officer | Option exercise | Stock Option (right to buy) | 1,600 | $0.00 | - | |
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Item 1.01, 9.01
Item 1.01, 2.03, 9.01
Item 2.02, 9.01
Item 5.07
Recent AMPX Form 144 notices of proposed sale
3An insider files Form 144 before selling restricted or control stock. It announces a planned sale. If the sale goes ahead, it shows up later on a Form 4.
| Filed | Filer | Relationship | Shares | Market value | Notice |
|---|---|---|---|---|---|
| KANG SUN | Director | 62,101 | $642K | View on EDGAR | |
| Constantin Ionel Stefan | OFFICER | 29,681 | $307K |
AMPX insider trading FAQ
What is the latest insider trade for AMPX?
Amprius Technologies, Inc. (AMPX) had 3 insider filings in the last 90 days, with the most recent on 2026-08-25. The full record for AMPX runs to 51 Form 4 filings, the earliest from 2024-10-25. InsiderAlpha adds new Form 4, Form 144 and 8-K filings as they arrive from SEC EDGAR.
How many insiders are buying AMPX stock?
No insider purchases of AMPX were filed in the last 90 days.
How many insiders are selling AMPX stock?
4 insider sales of AMPX were filed in the last 90 days, totaling $1.27M.
Where can I see AMPX SEC filings (Form 4, 10-K, 10-Q, 8-K)?
This page collects AMPX Form 4 insider transactions, Form 144 sale notices and 8-K filings in one place. Annual 10-K and quarterly 10-Q reports live on the company's SEC EDGAR page.
More Information Technology companies with insider activity
Recent insider filings
10The EDGAR links open each original Form 4, so you can check any number on this page against the filing it came from.
- - Kang Sun view on EDGAR
- - Constantin Ionel Stefan view on EDGAR
- - Thomas M. Stepien view on EDGAR
- - Kathleen A. Bayless view on EDGAR
- - Livingston Satterthwaite view on EDGAR
- - Donald R. Dixon view on EDGAR
- - Steven Chu view on EDGAR
- - Donald R. Dixon view on EDGAR
- - Thomas M. Stepien view on EDGAR
Related companies with recent insider activity
Learn more
- Insider selling: signal or noise?
- Why most insider sales are routine, and the few patterns worth a second look.
- Form 144 vs Form 4
- A Form 144 announces a planned sale; the Form 4 reports it after it happens.
- Insider activity in Information Technology
- Where AMPX's peers are being bought and sold.
- Every recent Form 4
- The market-wide feed, updated as filings arrive from SEC EDGAR.
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