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SEC EDGAR$CSTL

MAETZOLD DEREK J sold $13K of CSTL

MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 550 shares of CASTLE BIOSCIENCES INC (CSTL) at $22.92 on 2026-07-14 under a Rule 10b5-1 trading plan.

Original reporting
SEC EDGAR · MAETZOLD DEREK J
Published Jul 16, 2026, 8:16 PM UTC
Analysis
AlphAI AI DeskAI-generated
Added to AlphAI Jul 16, 2026, 8:28 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.
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AlphAI market briefInsider activity
Primary signal
$CSTL
Neutral
medium confidence
Mentioned
$CSTL
Relevance
2/10
AlphAI data visualization · based on SEC EDGAR
Decision brief

The 30-second read

$CSTLNeutralLow
01

Why it matters

The newest fact is the CEO’s reported open-market sale of 550 shares at $22.92 on 2026-07-14, with holdings after the trade of 21,479 shares.

02

Market read

This provides a fresh, primary-source datapoint on insider selling, but the modest size and 10b5-1 structure reduce fundamental interpretability.

03

What to watch

Traders may over-weight small insider sales; the more informative signal would be changes in buying activity, larger transactions, or non-10b5-1 trades.

Relevance 2/10Novelty 3/10Timing: SEC Form 4 filed 2026-07-16 for a 2026-07-14 insider sale.

Background

The article is an SEC Form 4 insider transaction disclosure for CASTLE BIOSCIENCES, Inc.

Company-level read

Ticker impact

$CSTLNeutralMedium confidence
Context

CASTLE BIOSCIENCES insider MAETZOLD DEREK J sold 550 shares on 2026-07-14 at $22.92 via a 10b5-1 plan, totaling $12,606.

Expected impact

Likely limited immediate price impact; any reaction would be sentiment-driven rather than fundamental.

Evidence & confidence

The filing is a routine Form 4 insider sale with stated 10b5-1 pre-arrangement, and the disclosed dollar value is modest relative to company-level fundamentals.

Market effects

Sector

No sector-level read-across; this is a single-company insider transaction.

Regional

None indicated.

Global

None indicated.

Counterpoint

What could challenge this read

Because the sale is explicitly under a 10b5-1 plan, it may reflect scheduled liquidity needs rather than bearish expectations.

Key entities

  • issuer
    CASTLE BIOSCIENCES INC

    US-listed biotechnology company, ticker CSTL, subject of the Form 4 insider sale disclosure.

  • insider
    MAETZOLD DEREK J

    President and Chief Executive Officer who executed the reported sale under a 10b5-1 plan.

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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