AlphAIAlphAI — Financial news for AI agents
SEC EDGAR$CSTL

MAETZOLD DEREK J sold $83K of CSTL (indirect holdings)

MAETZOLD DEREK J (Pres. & Chief Exec. Officer) sold 3,622 indirectly-held shares of CASTLE BIOSCIENCES INC (CSTL) at $22.92 across 6 trades 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.
About AlphAI AI DeskScoring methodologyReport an issue
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 disclosure provides transparency on insider liquidity and potential sentiment, but it does not include new company fundamentals, guidance, or regulatory/clinical catalysts.

02

Market read

Primarily a sentiment/positioning datapoint for CSTL, with limited direct trading edge absent additional fundamental news.

03

What to watch

Traders may over-weight insider sales; the more actionable signal would be any concurrent company-specific news (guidance, trial updates, financing) which is not present here.

Relevance 2/10Novelty 3/10Timing: Filed 2026-07-16, discloses sales executed 2026-07-14.

Background

The article is an SEC Form 4 insider transaction disclosure for CASTLE BIOSCIENCES, reporting an open-market sale by the CEO through an indirect holding structure.

Company-level read

Ticker impact

$CSTLNeutralMedium confidence
Context

CASTLE BIOSCIENCES CEO sold $83,016 of CSTL via an open-market sale under a pre-arranged 10b5-1 plan on 2026-07-14.

Expected impact

Likely limited, short-lived impact; watch for follow-on insider activity or unusual volume around the sale date.

Evidence & confidence

The filing is a Form 4 insider transaction (open-market sale) with a stated 10b5-1 plan, which typically reduces interpretive signal versus discretionary selling.

Market effects

Sector

Minimal; insider sale in a single biotech does not materially change sector fundamentals.

Regional

None indicated.

Global

None indicated.

Counterpoint

What could challenge this read

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

Key entities

  • issuer
    CASTLE BIOSCIENCES INC

    Subject of the Form 4 insider transaction disclosure (CSTL).

  • insider
    MAETZOLD DEREK J

    Pres. and Chief Exec. Officer reporting an open-market 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 →

Related articles

$CSTLMed

DecisionDx®-Melanoma Data at SDPA and Dermato-Onco2026 Support the Test's Ability to Refine Risk Assessment Beyond AJCC Staging

Castle Biosciences presented data on DecisionDx-Melanoma at SDPA and Dermato-Onco2026, showing the test can identify higher-risk patients with thin melanomas and provide individualized five-year recurrence-risk estimates. The studies suggest the test refines risk assessment beyond AJCC staging, aiding personalized care. According to the company, the test has been ordered over 260,000 times and is supported by extensive research.

prnewswire.com
$CSTLMed

Castle Bio (CSTL) Q3 2026 Earnings Call Transcript

Castle Bio (CSTL) reported Q3 2026 revenue of $102.9M, up 24% YoY, driven by 47% growth in TissueCypher test volume. Net cash from operations was $19.7M, with $278M in cash and equivalents. The company raised full-year revenue guidance to $385M-$395M, up from $365M-$375M. DecisionDx-Melanoma saw 5% YoY growth, while TissueCypher is expected to grow 50%-52% for the year.

finance.yahoo.com
$CSTLHigh

Castle Biosciences Reports Third Quarter 2026 Results

CASTLE BIOSCIENCES INC (CSTL) filed an SEC Form 8-K — Results of Operations and Financial Condition. Exhibit 99.1 Castle Biosciences Reports Third Quarter 2026 Results Delivered Q3 2026 revenue of $102.9 million, an increase of 24% over Q3 2025 TissueCypher ® test report volume increased 47% over Q3 2025 Raising full-year 2026 revenue guidance to $385-395 million from $365-375 m

SEC EDGAR 8-K
$CSTLHighAI 8/10

Castle Biosciences Reports Third Quarter 2026 Results

Castle Biosciences reported Q3 2026 revenue of $102.9M, up 24% YoY. TissueCypher test volume rose 47% YoY. The company raised full-year 2026 revenue guidance to $385-395M. Q3 net loss was $4.1M, with Adjusted EBITDA of $12.7M. The company presented new data on its DecisionDx-Melanoma test at EADV Congress 2026.

prnewswire.com
$CSTLMed

Late-Breaking EADV 2026 Data Support Use of DecisionDx®-Melanoma in SLNB Decision-Making and Risk-Aligned Post Surgical Management

Castle Biosciences presented data at EADV 2026 showing DecisionDx-Melanoma's ability to predict low SLN positivity and high recurrence risk in melanoma patients. The study involved 2,799 patients across 29 U.S. centers, with low-risk patients avoiding SLNB showing 99.6% five-year RFS. The test also stratified recurrence risk in early-stage, transected melanomas, supporting tailored surveillance. Castle Biosciences is a Nasdaq-listed company (CSTL).

prnewswire.com