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sellWeak cluster of 2

Richard K Prins sold $438k of AMPH

director at Amphastar Pharmaceuticals, Inc.. 10,000 shares at an average of $43.77, traded Dec 9, 2024, filed Dec 11, 2024.

Warning score
30
Value
$438k
10,000 shares
Holdings after
30,471
-25% from before
From 52-week low
-
no price yet
From 52-week high
-
no price yet

Score components

  • Role
    Director
    +15
  • Trade size
    $438k at market
    +17
  • Share of holdings sold
    Sold 25% of holdings
    +5
  • Cluster
    2 insiders selling within 14 days
    +8
  • Exercise and sell
    Shares came from an option exercise in the same filing
    -15

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.

This signal so far: 1m -16.5%, 3m -39.7%, 6m -40.2%.

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.

AMPHOct 9, 2026 · close 26.62
Since filing Dec 11, 2024: -38.9%SPY +31.0% · excess -69.9%

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 0001415889-24-029033, as filed. Open on EDGAR

DateTransactionSharesPriceValueHoldings afterFiled
Dec 9, 2024MOption exercise
Common Stock
+10,000$19.52$195k40,471Dec 11, 2024
Dec 9, 2024SOpen-market sale
Common Stock
-10,000$43.77$438k30,471Dec 11, 2024
Dec 9, 2024GGift
Common Stock
-410$0.00$030,061Dec 11, 2024
Dec 9, 2024MOption exercise
Stock Option (right to buy)derivative
-10,000$0.00$00Dec 11, 2024

Related signals

Other insiders at Amphastar Pharmaceuticals, Inc. and this insider’s other filings.

ScoreCompanyInsiderValueHoldingsFiled
20Weak
AMPHsell 210b5-1
Amphastar Pharmaceuticals, Inc.
William J Peters
CFO, EVP & TREASURER
$103k
4,139 shares
-2%
21Weak
AMPHsell 2
Amphastar Pharmaceuticals, Inc.
Rong Zhou
SENIOR EVP, PRODUCTION CENTER
$239k
10,000 shares
-6%
23Weak
AMPHsell
Amphastar Pharmaceuticals, Inc.
Rong Zhou
SENIOR EVP, PRODUCTION CENTER
$75k
3,187 shares
-2%
39Weak
AMPHsell 2
Amphastar Pharmaceuticals, Inc.
Richard K Prins
director
$162k
7,973 shares
-21%
7Weak
AMPHsell 210b5-1
Amphastar Pharmaceuticals, Inc.
William J Peters
CFO, EVP & TREASURER
$184k
8,180 shares
-5%
21Weak
AMPHsell 2
Amphastar Pharmaceuticals, Inc.
Rong Zhou
SENIOR EVP, PRODUCTION CENTER
$256k
9,787 shares
-7%
33Weak
AMPHsell 2
Amphastar Pharmaceuticals, Inc.
Floyd F. Petersen
director
$108k
4,163 shares
-6%
23Weak
AMPHsell 2
Amphastar Pharmaceuticals, Inc.
Richard K Prins
director
$113k
4,179 shares
-11%
30Weak
AMPHsell 2
Amphastar Pharmaceuticals, Inc.
Floyd F. Petersen
director
$442k
16,679 shares
-18%
0Weak
AMPHsell10b5-1
Amphastar Pharmaceuticals, Inc.
Floyd F. Petersen
director
$13k
500 shares
-1%

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.

Richard K Prins sold $438k of AMPH | InsiderTell