Insider Cluster (3 insiders) ·Filed Sep 2, 2026
Insider cluster: 3 insiders, $0.4M total
Actionable Insight • Neutral
Insider selling is routine and immaterial. No trading signal from this cluster. Monitor upcoming earnings or clinical catalysts for real stock-moving events.
Latest settled — T+20d ⚠ clustered
CSTL ▲ +8.91% at T+20d
NEUTRAL call +8.91% · α vs SPY +10.10% · entry $32.65 → $35.56
Latest observation: T+35 -15.68% FF3 residual α
T+1d
+0.80%
call +0.80% · α +1.18%
$32.91
settled 8w ago
T+5d
-0.98%
call -0.98% · α +0.17%
$32.33
settled 7w ago
T+20d
+8.91%
call +8.91% · α +10.10%
$35.56
settled 26d ago
T+60d
Pending
in 4w
Price Chart
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Executive Summary
Three C-suite insiders at Castle Biosciences (CEO, COO, CCO) sold a total of $373K in open-market transactions over a one-week window. The total sales represent less than 0.04% of the company's $1.0B market cap, making this a routine, immaterial cluster with no predictive signal.
Key Financial Metrics
Direction
selling
Total Value
$373.0K
Insiders
3
Key Facts
- CEO Derek Maetzold sold ~$71K worth of shares on Aug 28, 2026, after exercising options (non-cash).
- COO Kristen Oelschlager sold ~$245K worth of shares on Aug 25, 2026.
- CCO Tobin Juvenal sold ~$57K worth of shares on Aug 31, 2026.
- Total open-market sales of $373K represent ~0.037% of CSTL's $1.0B market cap.
- All three sellers are C-suite executives, but the dollar amounts are trivial relative to company size.
Financial Impact
Total insider sales of $373K, less than 0.04% of market cap — no material financial impact.
Risk Factors
- None from this filing; insider activity is too small to indicate any change in fundamentals.
Market Snapshot
Exchange
Nasdaq
Sector
Services-Medical Laboratories
Analyst Consensus
93% bullish (15 analysts)
Investment Themes
Documents Analyzed
This report is based on 1 SEC document filed with EDGAR.
| Document | Accession Number |
|---|---|
| CLUSTER Data (Synthetic) | cluster-CSTL-1788379729071 |
31 reports for CSTL
60% Hit rate @ T+1 Went positive at some point 9 of 10 best @ T+60▲ +27.32%
Filters
Rows
| Type | Now | ||||
|---|---|---|---|---|---|
Oct 21, 2026 5d ago | Insider Cluster | $33.19 $33.08 | ▼ −0.33% | ▲ +0.19% | $33.30 (+0.33%) |
Oct 5, 2026 21d ago | 144 | $33.36 $33.00 | ▼ −1.08% | ▼ −0.84% | $33.30 (−0.18%) |
Oct 5, 2026 21d ago | Insider Cluster | $33.36 $33.00 | ▼ −1.08% | ▼ −0.84% | $33.30 (−0.18%) |
Sep 23, 2026 4w ago | Insider Cluster | $35.19 $35.81 | ▼ −1.76% | ▼ −1.22% | $33.30 (+5.37%) |
Sep 16, 2026 5w ago | Insider Cluster | $36.78 $35.34 | ▼ −3.92% | ▼ −4.04% | $33.30 (−9.46%) |
Sep 11, 2026 6w ago | 144 | $33.44 $35.50 | ▲ +6.16% | ▲ +6.62% | $33.30 (−0.42%) |
Sep 3, 2026 7w ago | Insider Cluster | $32.91 $32.76 | ▲ +0.46% | ▼ −0.09% | $33.30 (−1.19%) |
Sep 2, 2026 7w ago | Insider Cluster | $32.65 $32.91 | ▲ +0.80% | ▲ +1.18% | $33.30 (+1.99%) |
Sep 1, 2026 7w ago | Insider Cluster | $33.42 $32.65 | ▼ −2.30% | ▼ −3.35% | $33.30 (−0.36%) |
Aug 27, 2026 8w ago | Insider Cluster | $33.50 $33.03 | ▼ −1.40% | ▼ −1.10% | $33.30 (−0.60%) |
Showing 10 of 31
US Market Status
Market Closed — Opens in 1h 40m
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