CSTL

Castle Biosciences Inc$24.23 0.87%
Health CareUSCUSIP 14843C105· EOD Jul 16, 2026◍ Confluence graph
Tracked 13F Holders
148
-3 QoQ
13F Value (tracked)
$627.0M
Insider Net · 180d
-$5.5M
0↑ 5↓
Recent Filings
0
Smart-money sentimentMixed
BearishBullish
13F funds (latest Q)34 adding · 19 trimming
Insider net (180d)-$5.5M

Price & smart-money activity

$24.23 0.87%5Y -63.9%
$6.38$25.51$44.63$63.75$82.88202120222023202420252026323362830324030252422140131292736232823222472423302225282729422437305794534738364632414444421363
Hover for who · click for detailEnd-of-day closing prices52w $14.65 – $43.04
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Ask your agent what changed in CSTL

This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.

Copy-paste
curl -H "Authorization: Bearer YOUR_API_KEY" \
  "https://arkolith.com/api/v1/stocks/CSTL/capital-change-brief"
Ask your agent
Use Arkolith's capital_change_brief for CSTL.
Tell me what changed, whether insider activity
corroborates it, and cite the SEC evidence.

Top institutional holders

148 tracked 13F filers
#FundPosition valueSharesLast moveAs ofHistory
1BlackRock, Inc.
$73.2M
3.0M
−3.9%
Reduced · −122K sh
Q1 2026
2RTW INVESTMENTS, LP
$67.7M
2.8M
+30%
Added · +643K sh
Q1 2026
3PRINCIPAL FINANCIAL GROUP INC
$43.5M
1.8M
−2.1%
Reduced · −38K sh
Q1 2026
4Portolan Capital Management, LLC
$33.1M
1.4M
−22%
Reduced · −379K sh
Q1 2026
5VANGUARD CAPITAL MANAGEMENT LLC
$28.9M
1.2M
New
+1.2M sh
Q1 2026
6DIMENSIONAL FUND ADVISORS LP
$25.5M
1.0M
−9.1%
Reduced · −104K sh
Q1 2026
7SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC
$23.1M
941K
−11%
Reduced · −118K sh
Q1 2026
8VANGUARD PORTFOLIO MANAGEMENT LLC
$21.2M
862K
New
+862K sh
Q1 2026
9Allianz Asset Management GmbH
$19.9M
811K
+30%
Added · +189K sh
Q1 2026
10STATE STREET CORP
$18.9M
769K
+4.4%
Added · +33K sh
Q1 2026
11GEODE CAPITAL MANAGEMENT, LLC
$17.9M
728K
+1.8%
Added · +13K sh
Q1 2026
12Qube Research & Technologies Ltd
$13.7M
560K
+138%
Added · +324K sh
Q1 2026
13PALISADE CAPITAL MANAGEMENT, LP
$13.2M
536K
−5.6%
Reduced · −32K sh
Q1 2026
14RENAISSANCE TECHNOLOGIES LLC
$13.1M
533K
+8.1%
Added · +40K sh
Q1 2026
15Nuveen, LLC
$12.8M
522K
−0.5%
Reduced · −3K sh
Q1 2026
16MORGAN STANLEY
$10.5M
429K
+111%
Added · +225K sh
Q1 2026
17EVENTIDE ASSET MANAGEMENT, LLC
$9.5M
386K
+27%
Added · +81K sh
Q1 2026
18Connor, Clark & Lunn Investment Management Ltd.
$9.3M
377K
−2.9%
Reduced · −11K sh
Q1 2026
19MILLENNIUM MANAGEMENT LLC
$8.7M
353K
+14%
Added · +44K sh
Q1 2026
20GOLDMAN SACHS GROUP INC
$8.4M
341K
+19%
Added · +54K sh
Q1 2026
21SCHRODER INVESTMENT MANAGEMENT GROUP
$7.0M
299K
−39%
Reduced · −193K sh
Q1 2026
22WASATCH ADVISORS LP
$6.7M
279K
−39%
Reduced · −176K sh
Q2 2026
23NORTHERN TRUST CORP
$6.7M
273K
+4.1%
Added · +11K sh
Q1 2026
24SILVERCREST ASSET MANAGEMENT GROUP LLC
$6.6M
269K
+31%
Added · +64K sh
Q1 2026
25KORNITZER CAPITAL MANAGEMENT INC /KS
$6.5M
264K
−1.2%
Reduced · −3K sh
Q1 2026

Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.

Fund activity: latest quarter

Opened (NEW)
4
funds
Added
30
funds
Reduced
19
funds
Exited
0
funds

Insider activity (Form 4)

Full insider page →
Buys · 180d
$0
0 insiders
Sells · 180d
$5.5M
5 insiders
Net
-$5.5M
102 P/S txns
Signal
Net Selling
open-market
DateInsiderRoleActionSharesValue
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorOption exercise (M)550$0
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorSell (S)278$6K
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorSell (S)278$6K
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorSell (S)278$6K
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorSell (S)278$6K
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorSell (S)1K$26K
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorSell (S)1K$31K
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorSell (S)550$13K
Jul 14, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorOption exercise (M)550$1K
Jul 1, 2026Oelschlager Kristen MChief Operating OfficerSell (S)400$10K
Jul 1, 2026Oelschlager Kristen MChief Operating OfficerSell (S)8K$200K
Jul 1, 2026MAETZOLD DEREK JPres. & Chief Exec. Officer, DirectorOption exercise (M)6K$0

Institutional ownership over time

147 funds+25 since Q3 2024
075150Q3 2024Q1 2025Q3 2025Q1 2026
funds holding aggregate valuelatest $631.3M

Funds that own CSTL also own

CompanyCo-held byCombined value
MICROSOFT CORPMSFT55 funds$26.7B
BROADCOM INCAVGO55 funds$15.5B
AMAZON.COM INCAMZN54 funds$19.3B
META PLATFORMS INC-CLASS AMETA54 funds$12.5B
NVIDIA CORPNVDA53 funds$39.2B
ALPHABET INC-CL AGOOGL53 funds$17.9B
JPMORGAN CHASE & COJPM53 funds$7.7B
ELI LILLY & COLLY53 funds$6.7B
MICRON TECHNOLOGY INCMU53 funds$6.1B
UNITEDHEALTH GROUP INCUNH53 funds$2.5B
CENTENE CORPCNC53 funds$540.0M
COSTCO WHOLESALE CORPCOST52 funds$4.6B

Ranked by how many of CSTL's institutional holders also hold each name, a cross-fund conviction signal. Via the MCP server (ticker.co_held).

Recent filings

0 shown

No filings captured for this ticker in the live stream yet.

Browse more

13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for CSTL. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes. Every panel above is one call to the Arkolith API & MCP server.