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Insider Cluster (2 insiders) ·Filed Sep 16, 2026

CSTL

CASTLE BIOSCIENCES INC
NEUTRAL
Impact 2/10
Horizondays Processed1mo ago
Insider cluster: 2 insiders, $110K total
Actionable Insight • Neutral

Insider sales are minimal and routine — no signal of adverse business developments. Monitor upcoming earnings or pipeline catalysts for any fundamental changes.

DirectionNeutral
Confidencehigh
Horizondays
Latest settled — T+20d
CSTL ▼ -8.10% at T+20d
NEUTRAL call -8.10% · α vs SPY -9.56% · entry $36.78 → $33.80
Next anchor: T+60d in 6w
Latest observation: T+26 -26.35% FF3 residual α
Entry = T+0 close
Sep 17, 2026
via day close
T+1d
-3.92%
call -3.92% · α -4.04%
$35.34
settled 6w ago
T+5d
-4.32%
call -4.32% · α -5.17%
$35.19
settled 5w ago
T+20d
-8.10%
call -8.10% · α -9.56%
$33.80
settled 12d ago
T+60d
Pending
in 6w

Price Chart

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Executive Summary

Two Castle Biosciences insiders, including the CEO and CCO, sold a combined $110K in shares over a week. The CEO's sale of $3K is trivial, while the CCO's $107K sale is modest relative to the company's market cap. Both sales appear routine and non-informative, with no indication of 10b5-1 plans but likely tied to tax or liquidity needs.

Key Financial Metrics

Direction
selling
Total Value
$110.0K
Insiders
2

Key Facts

  • CEO Derek Maetzold sold 83 shares for ~$3K on 2026-09-11
  • CCO Tobin Juvenal sold 3,300 shares for ~$107K on 2026-09-14
  • Total insider sales of $110K represent a negligible fraction of market cap
  • No open-market purchases were reported in the cluster

Financial Impact

Total sales of $110K are immaterial relative to market cap (likely <0.1%)

Risk Factors

  • No material insider selling signal; cluster is too small to indicate informed trading

Investment Themes

Documents Analyzed

This report is based on 1 SEC document filed with EDGAR.

DocumentAccession Number
CLUSTER Data (Synthetic)cluster-CSTL-1789620342884
31 reports for CSTL
Performance horizon
60% Hit rate @ T+1 6 of 10 directional calls Went positive at some point 9 of 10 best @ T+60▲ +27.32%Mar 5, 2026
Filters
Rows
Reports for CSTL — sortable, filterable
TypeNow
Oct 21, 2026
5d ago
Insider Cluster
NEUTRAL ★ 3/10
$33.19 $33.08▼ −0.33%▲ +0.19%$33.30 (+0.33%)
Oct 5, 2026
21d ago
144
NEUTRAL ★ 4/10
$33.36 $33.00▼ −1.08%▼ −0.84%$33.30 (−0.18%)
Oct 5, 2026
21d ago
Insider Cluster
NEUTRAL ★ 2/10
$33.36 $33.00▼ −1.08%▼ −0.84%$33.30 (−0.18%)
Sep 23, 2026
4w ago
Insider Cluster
BEARISH ★ 4/10
$35.19 $35.81▼ −1.76%▼ −1.22%$33.30 (+5.37%)
Sep 16, 2026
5w ago
Insider Cluster
NEUTRAL ★ 2/10
$36.78 $35.34▼ −3.92%▼ −4.04%$33.30 (−9.46%)
Sep 11, 2026
6w ago
144
NEUTRAL ★ 4/10
$33.44 $35.50▲ +6.16%▲ +6.62%$33.30 (−0.42%)
Sep 3, 2026
7w ago
Insider Cluster
BEARISH ★ 4/10
$32.91 $32.76▲ +0.46%▼ −0.09%$33.30 (−1.19%)
Sep 2, 2026
7w ago
Insider Cluster
NEUTRAL ★ 2/10
$32.65 $32.91▲ +0.80%▲ +1.18%$33.30 (+1.99%)
Sep 1, 2026
7w ago
Insider Cluster
NEUTRAL ★ 2/10
$33.42 $32.65▼ −2.30%▼ −3.35%$33.30 (−0.36%)
Aug 27, 2026
8w ago
Insider Cluster
NEUTRAL ★ 4/10
$33.50 $33.03▼ −1.40%▼ −1.10%$33.30 (−0.60%)
Showing 10 of 31

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Report published Sep 16, 2026