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SEC EDGAR$CSTL

MAETZOLD DEREK J sold $274K of CSTL

MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 8,580 shares of CASTLE BIOSCIENCES INC (CSTL) at $31.91 ($0.27M total) on 2026-10-19 under a Rule 10b5-1 trading plan.

Original reporting
SEC EDGAR · MAETZOLD DEREK J
Published Oct 21, 2026, 8:18 PM UTC
Analysis
AlphAI AI DeskAI-generated
Added to AlphAI Oct 21, 2026, 9:00 PM UTC. Informational, not investment advice.
How this was made
AlphAI summarizes source reporting and applies a structured AI analysis for relevance, timing, sentiment and ticker impact. Always verify material claims with the original publisher.
About AlphAI AI DeskScoring methodologyReport an issue
AlphAI market briefInsider activity
Primary signal
$CSTL
Bearish
medium confidence
Mentioned
$CSTL
Relevance
3/10
AlphAI data visualization · based on SEC EDGAR
Decision brief

The 30-second read

$CSTLBearishLow
01

Why it matters

The sale is modest in dollar terms but may be interpreted as a lack of confidence, potentially prompting a small sell‑off.

02

Market read

Insider sales by top executives can affect short‑term price dynamics, especially for small‑cap biotech stocks.

03

Timing

post‑market

Relevance 3/10Novelty 3/10Timing: post‑market

Background

Form 4 filing discloses an insider transaction by the company's chief executive.

Company-level read

Ticker impact

$CSTLBearishMedium confidence
Context

CEO Derek Maetzold sold 8,580 shares for $273,787 via a 10b5‑1 plan.

Expected impact

likely slight downward pressure as investors price in the insider sell

Evidence & confidence

The sale is modest but involves the CEO, which can influence short‑term sentiment.

Key entities

  • company
    Castle Biosciences Inc.

    Biotech firm listed on NASDAQ under ticker CSTL.

  • person
    Derek Maetzold

    President & Chief Executive Officer of Castle Biosciences.

Read at source← All news

Full insider trading history

This story covers one filing. See everything behind it: every insider buy and sell on record, 10b5-1 plans, late filings, and which officers and directors are trading.

CSTL insider trading history →

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