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sellWeak cluster of 310b5-1 plan

Derek J Maetzold sold $512k of CSTL

Pres. & Chief Exec. Officer at CASTLE BIOSCIENCES INC. 14,496 shares at an average of $35.33, traded Sep 21, 2026, filed Sep 23, 2026.

Warning score
33
Value
$512k
14,496 shares
Holdings after
9,550
-48% from before
From 52-week low
+93%
low $18.15, close $34.99
From 52-week high
-19%
high $43.04, as of Sep 21, 2026

Score components

  • Role
    CEO
    +25
  • Trade size
    $512k at market
    +18
  • Share of holdings sold
    Sold 48% of holdings
    +10
  • Cluster
    3 insiders selling within 14 days
    +15
  • 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.

CSTLOct 9, 2026 · close 34.42
Since filing Sep 23, 2026: -1.3%SPY +1.4% · excess -2.7%

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 0001628280-26-063221, as filed. Open on EDGAR

DateTransactionSharesPriceValueHoldings afterFiled
Sep 21, 2026MOption exercise
Common Stock10b5-1
+8,580$2.39$21k30,05920 d ago
Sep 21, 2026SOpen-market sale
Common Stock10b5-1
-8,580$35.33$303k21,47920 d ago
Sep 21, 2026SOpen-market sale
Common Stockindirect: By The Maetzold Descendants 2020 Trust10b5-1
-3,198$35.33$113k11,23620 d ago
Sep 21, 2026SOpen-market sale
Common Stockindirect: By Derek Maetzold 2020 Irrevocable Trust10b5-1
-2,718$35.33$96k9,55020 d ago
Sep 21, 2026MOption exercise
Stock option (right to buy)derivative10b5-1
-8,580$0.00$08,16520 d ago

Related signals

Other insiders at CASTLE BIOSCIENCES INC and this insider’s other filings.

ScoreCompanyInsiderValueHoldingsFiled
33Weak
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Derek J Maetzold
Pres. & Chief Exec. Officer
$516k
14,496 shares
-49%
16Weak
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Kristen M Oelschlager
Chief Operating Officer
$149k
4,153 shares
-24%
28Weak
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Tobin W Juvenal
Chief Commercial Officer
$232k
6,577 shares
-11%
27Weak
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Tobin W Juvenal
Chief Commercial Officer
$223k
6,600 shares
-10%
32Weak
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Derek J Maetzold
Pres. & Chief Exec. Officer
$465k
14,518 shares
-48%
16Weak
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Kristen M Oelschlager
Chief Operating Officer
$139k
4,152 shares
-24%
17Weak
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Tobin W Juvenal
Chief Commercial Officer
$57k
1,730 shares
-3%
45Moderate
CSTLsell 310b5-1
CASTLE BIOSCIENCES INC
Derek J Maetzold
Pres. & Chief Exec. Officer
$616k
18,560 shares
-55%
25Weak
CSTLsell 210b5-1
CASTLE BIOSCIENCES INC
Kristen M Oelschlager
Chief Operating Officer
$178k
8,587 shares
-22%
12Weak
CSTLsell 210b5-1
CASTLE BIOSCIENCES INC
Derek J Maetzold
Pres. & Chief Exec. Officer
$86k
4,172 shares
-19%

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.