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SEC EDGAR$CSTL

MAETZOLD DEREK J sold $214K of CSTL (indirect holdings)

MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 5,916 indirectly-held shares of CASTLE BIOSCIENCES INC (CSTL) at an average of $36.10 ($36.00–$36.81, $0.21M total) across 4 trades on 2026-11-02 under a Rule 10b5-1 trading plan.

Original reporting
SEC EDGAR · MAETZOLD DEREK J
Published Nov 4, 2026, 9:07 PM UTC
Analysis
AlphAI AI DeskAI-generated
Added to AlphAI Nov 4, 2026, 9:09 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
Neutral
high confidence
Mentioned
$CSTL
Relevance
3/10
AlphAI data visualization · based on SEC EDGAR
Decision brief

The 30-second read

$CSTLNeutralLow
01

Why it matters

Provides transparency on insider holdings; modest sell may be noted by short‑term traders.

02

Market read

Insider sale of modest size; limited trading relevance.

03

What to watch

Potential tax planning or liquidity needs for the executive.

Relevance 3/10Novelty 3/10Timing: post‑market filing on 2026‑11‑04

Background

SEC Form 4 filing discloses insider transactions for public companies.

Company-level read

Ticker impact

$CSTLNeutralHigh confidence
Context

Form 4 shows CEO sold ~214k shares at $36 per share, reducing his stake to 1,396 shares.

Expected impact

likely modest pressure as market prices in the insider sell.

Evidence & confidence

The sale is under $1M and represents a small remaining holding, typical for diversification; no material impact expected.

Market effects

Sector

Minimal effect on biotech sector; insider sales are routine.

Regional

No regional impact.

Global

Limited to investors tracking insider activity.

Counterpoint

What could challenge this read

The sale could be unrelated to company fundamentals; price may remain stable.

Key entities

  • company
    Castle Biosciences Inc.

    Biotech firm listed on NASDAQ under CSTL.

  • person
    Derek J. 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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