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sellWeak cluster of 210b5-1 plan

Kang Sun sold $11M of AMPX

Chief Executive Officer at Amprius Technologies, Inc.. 1,000,000 shares at an average of $10.60, traded Nov 17, 2025, filed Nov 19, 2025.

Warning score
33
Value
$11M
1,000,000 shares
Holdings after
1,472,306
-40% from before
From 52-week low
+528%
low $1.66, close $10.43
From 52-week high
-29%
high $14.61, as of Nov 17, 2025

Score components

  • Role
    CEO
    +25
  • Trade size
    $10.6M at market
    +25
  • Share of holdings sold
    Sold 40% of holdings
    +10
  • Cluster
    2 insiders selling within 14 days
    +8
  • Exercise and sell
    Shares came from an option exercise in the same filing
    -15
  • 10b5-1 plan
    Pre-scheduled under a 10b5-1 plan
    -20

What happened after comparable sells

Same side and tier, against the S&P 500, at 1, 3 and 6 months. Shown to Pro users; the whole table is on the backtest page.

Price around the trade, and since

From a quarter before the trade to today. The arrow is the trade, the circle the day the filing reached EDGAR, which is the first day anyone outside could act; the dotted line is the S&P 500 rebased to that day's close.

AMPXOct 9, 2026 · close 9.44
Since filing Nov 19, 2025: -12.7%SPY +18.8% · excess -31.4%

Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value; the dashed line is the close on the filing day, the dotted line SPY rebased to it.Charts by TradingView Lightweight Charts™

Rows in this filing

Every transaction in Form 4 0001476220-25-000018, as filed. Open on EDGAR

DateTransactionSharesPriceValueHoldings afterFiled
Nov 17, 2025MOption exercise
Common stock10b5-1
+202,934$0.98$199k1,675,240Nov 19, 2025
Nov 17, 2025MOption exercise
Common stock10b5-1
+727,950$0.05$36k2,403,190Nov 19, 2025
Nov 17, 2025MOption exercise
Common stock10b5-1
+27,463$0.62$17k2,430,653Nov 19, 2025
Nov 17, 2025MOption exercise
Common stock10b5-1
+41,653$0.62$26k2,472,306Nov 19, 2025
Nov 17, 2025SOpen-market sale
Common stock10b5-1
-1,000,000$10.60$11M1,472,306Nov 19, 2025
Nov 17, 2025MOption exercise
Stock Option (right to buy)derivative10b5-1
-202,934$0.00$00Nov 19, 2025
Nov 17, 2025MOption exercise
Stock Option (right to buy)derivative10b5-1
-727,950$0.00$00Nov 19, 2025
Nov 17, 2025MOption exercise
Stock Option (right to buy)derivative10b5-1
-27,463$0.00$0180,802Nov 19, 2025
Nov 17, 2025MOption exercise
Stock Option (right to buy)derivative10b5-1
-41,653$0.00$00Nov 19, 2025

Related signals

Other insiders at Amprius Technologies, Inc. and this insider’s other filings.

ScoreCompanyInsiderValueHoldingsFiled
53Moderate
AMPXsell 2
Amprius Technologies, Inc.
Donald R Dixon
director
$1.5M
85,000 shares
-19%
52Moderate
AMPXsell 4
Amprius Technologies, Inc.
Donald R Dixon
director
$765k
40,000 shares
-8%
46Moderate
AMPXsell 4
Amprius Technologies, Inc.
Thomas M Stepien
Chief Executive Officer
$42k
2,000 shares
-0%
44Moderate
AMPXsell 4
Amprius Technologies, Inc.
Donald R Dixon
director
$320k
17,895 shares
-4%
30Weak
AMPXsell 4
Amprius Technologies, Inc.
Kang Sun
Chief Executive Officer
$6,121
356 shares
-0%
37Weak
AMPXsell 4
Amprius Technologies, Inc.
Constantin Ionel Stefan
Chief Technology Officer
$55k
3,208 shares
-0%
48Moderate
AMPXsell 4
Amprius Technologies, Inc.
Thomas M Stepien
Chief Executive Officer
$75k
4,375 shares
-1%
55Moderate
AMPXsell 4
Amprius Technologies, Inc.
Kang Sun
Chief Executive Officer
$1.0M
67,796 shares
-5%
47Moderate
AMPXsell 4
Amprius Technologies, Inc.
Constantin Ionel Stefan
Chief Technology Officer
$426k
28,812 shares
-3%
64Notable
AMPXsell 4
Amprius Technologies, Inc.
Thomas M Stepien
Chief Executive Officer
$898k
60,702 shares
-8%

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.

Kang Sun sold $11M of AMPX | InsiderTell