Stock Analysis
Data Source: SEC EDGAR 13F
Updated Hourly

Castle Biosciences Inc (CSTL)

183 + Investors. Track Smart Money conviction in CSTL. See who's accumulating, reducing, or initiating positions.

Current Price
-- USD
Analyst Target
-- (0 analysts)
Upside
0.00%
Net Flow Q/Q
↓ -9
Streak
1Q ▼
Buyers last Q
52%

Smart Money Signals — CSTL

Based on 185 hedge funds · latest filing: 2026 Q1 · updated quarterly

📉

Selling streak — 1 quarter in a row

last 6Q
For 1 consecutive quarter, more hedge funds reduced or closed their CSTL positions than added to them. Sustained institutional selling is a meaningful warning sign — these are professionals with deep research teams collectively deciding to exit.
🏔️

At the ownership peak (95% of max)

95% of all-time peak
185 hedge funds hold CSTL right now — the highest count in 3.0 years. When ownership is this concentrated, any bad news can trigger a chain reaction: one big fund sells, others follow. This is a classic 'crowded trade' — high popularity doesn't equal safety.
〰️

Stable — ownership unchanged year-over-year

fund count last 6Q
The number of hedge funds holding CSTL is almost the same as a year ago (+5 funds, +3% change). No significant rush to buy or sell — institutional backing is holding steady.
🟡

Slight buying edge — 52% buying

102 buying95 selling
Last quarter: 102 funds bought or added vs 95 that reduced or exited. It's nearly a 50/50 split — some institutions are convinced, others are taking profits. This mixed picture is normal near price highs.
⚠️

Fewer new buyers each quarter (-16 vs last Q)

new funds entering per quarter
Funds opening this position for the first time: 16 → 34 → 43 → 27. Each quarter fewer new institutions are entering. This usually means most funds that wanted in are already in — the stock is well-known but the pool of potential new buyers is shrinking.
🔒

56% of holders stayed for 2+ years

■ 56% conviction (2yr+) ■ 26% medium ■ 18% new
103 out of 185 hedge funds have held CSTL for over 2 years without selling. Long-term investors are generally harder to shake out during market stress, creating a stable ownership base that limits the risk of sudden capitulation.
💎

Buying through price weakness — shares +1%, value -38%

Value
-38%
Shares
+0%
Last quarter: funds added +1% more shares while total portfolio value only changed -38%. Institutions were buying while the price was falling — a high-conviction accumulation signal. They're deliberately loading up on the dip.
📈

Growing discovery — still being found

31 → 16 → 34 → 43 → 27 new funds/Q
New funds entering each quarter: 16 → 34 → 43 → 27. A growing number of institutions are discovering CSTL each quarter. The narrative is still spreading — leaving room for ongoing capital accumulation.
🏛️

Veteran-anchored — 61% veterans vs 22% newcomers

■ 61% veterans ■ 17% 1-2yr ■ 22% new
Entry-cohort mix of 189 holders: 115 (61%) are 2+ year veterans, 32 entered 1–2 years ago, and 42 (22%) joined within the past year. A veteran-weighted cap table skews toward institutional memory over fresh momentum.
✅

Strong quality — 29% AUM from major funds

29% from top-100 AUM funds
43 of 185 holders rank in the top 100 by AUM, accounting for 29% of total institutional value held. A meaningful share of the ownership value comes from the most well-resourced institutions.
3.5
out of 10
Low Exit Risk
Exit risk score 3.5/10 — low institutional crowding. Ownership is below peak levels, holder base is relatively sticky, and buying momentum is positive.

Methodology note: these Smart Money cards use consecutive 13F disclosure snapshots, not trade-by-trade execution data. "Buying", "selling", "new holders", and "trimmed" refer to quarter-over-quarter changes in reported holders, aggregate shares, or disclosed position values between filings. They are useful for ownership regime analysis and crowding, but they do not imply exact trade timing on the filing date.

Institutional Sentiment Summary — CSTL

In 2026 Q1, 102 hedge funds were net buyers of CSTL (27 opened a new position, 75 added to an existing one), while 95 reduced or exited (59 trimmed, 36 sold completely) — a 52% buyer ratio, indicating a slight buying edge. 29% of total institutional value in CSTL is held by top-100 AUM funds, reflecting strong institutional quality. Net fund flow last quarter: -9 funds (more exits than new entries). Total institutional holders: 185.

Hedge Fund Ownership: CSTL

How many hedge funds hold CSTL — quarterly history vs. share price
Quarterly hedge fund ownership of CSTL vs. share price

Market Analysis: CSTL

Analyst Price Targets

Avg. Price Target
--

Analyst Recommendations

Stock Performance

Real-time

Company Profile: CSTL

-- --

Institutional ownership data sourced from SEC EDGAR Form 13F-HR filings.

Is It Too Late to Buy Castle Biosciences Inc (CSTL) Based on Hedge Fund 13F Filings?

Signal Freshness measures how much CSTL has moved relative to its sector benchmark (XLV) since the 2026 Q1 13F filing. A stock that has barely outrun its sector is still a relatively fresh entry point — the fund's thesis has not yet been priced in by the broader market.

Since Quarter End March 31, 2026 · 77d ago
CSTL
-16.7%
XLV
+4.3%

CSTL outperformed XLV by -21.0% since March 31, 2026.

Since 13F Filing Date May 15, 2026 · 32d ago
CSTL
+7.0%
XLV
+5.4%

Since the filing became public, CSTL outperformed XLV by +1.6% .

Interpretation: The stock is tracking its sector benchmark closely. The signal remains fresh and the entry point is still near the fund's implied reference. Learn more →

Smart Money Signal ?
Limited Smart Money Interest

No strong consensus or elite conviction detected among institutional holders.

18 top-rated funds 1 high-conviction
Consensus
5.6
/ 10
breadth
×
Elite
1.0
/ 10
conviction
Hedge Fund Positioning: CSTL
183 + Investors

Track Smart Money conviction in CSTL. See who's accumulating, reducing, or initiating positions.

Metric All 13F Filers (2026 Q1) Prior (2025 Q4) Change
Funds Holding 183 194 -5.67%
13F Shares 28M 27M 0.87%
Total Value $657M $1.06B -38.23%
New Positions 26 43 -17
Increased Positions 73 64 +9
Closed Positions 37 19 +18
Reduced Positions 58 70 -12
Total Calls 3 3 -
Total Puts 1 0 100%
PUT/CALL Ratio 0.33 0.0 Bullish

Statistics: CSTL

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Valuation Measures Data as of: --

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PEG Ratio (5yr expected) --
Price/Sales (ttm) --
Price/Book (mrq) --
Enterprise Value/Revenue --
Enterprise Value/EBITDA --
Beta (5Y Monthly) --
Short Ratio (Days to Cover) --
Short % of Float --

Financial Highlights

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Profit Margin --
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Income Statement & Cash Flow
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Net Income Avi to Common (ttm) --
Diluted EPS (ttm) --
Total Cash (mrq) --
Total Debt/Equity (mrq) --
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Institutional Holders (2026 Q1)

183 + investors

Explore institutional interest and hedge fund ownership dynamics. Analyze portfolio weights, new positions, and conviction trends in CSTL. Verified SEC 13F-HR filings.

QUARTER:
Top 25 CSTL holders by conviction (% of portfolio weight) — 2026 Q1 · Source: SEC Form 13F
# Investor % of Portfolio Shares Mkt Value
1 AIGH Capital Management LLC 1.98% 590,601 $14.5M
2 Portolan Capital Management, LLC 1.76% 1,350,283 $33.1M
3 Rtw Investments, LP 0.67% 2,758,335 $67.7M
4 Summit Partners Public Asset Management, LLC 0.62% 940,685 $23.1M
5 Formula Growth Ltd 0.51% 46,000 $1.1M
6 Palisade Capital Management, LP 0.44% 535,884 $13.2M
7 Perkins Capital Management Inc 0.35% 15,415 $378K
8 Parkman Healthcare Partners LLC 0.32% 126,150 $3.1M
9 Green Alpha Advisors, LLC 0.24% 9,945 $244K
10 Campbell & CO Investment Adviser LLC 0.21% 148,824 $3.7M
11 Birchview Capital, LP 0.18% 12,900 $317K
12 Eventide Asset Management, LLC 0.16% 386,425 $9.5M
13 Kornitzer Capital Management Inc /Ks 0.14% 264,396 $6.5M
14 Bridgeway Capital Management, LLC 0.13% 255,184 $6.3M
15 Fox Run Management, L.L.C. 0.11% 26,247 $618K
16 TritonPoint Partners, LLC 0.10% 10,777 $265K
17 Nebula Research & Development LLC 0.08% 44,472 $908K
18 Wasatch Advisors LP 0.07% 455,036 $11.2M
19 Advisors Capital Management, LLC 0.07% 248,376 $6.1M
20 First Bank & Trust 0.07% 16,504 $405K
21 Dynamic Technology Lab Private Ltd 0.06% 15,913 $391K
22 SummitTX Capital, L.P. 0.05% 67,033 $1.6M
23 Silvercrest Asset Management Group LLC 0.05% 268,535 $6.6M
24 Inspire Investing, LLC 0.04% 21,045 $517K
25 AlphaQuest LLC 0.04% 17,116 $666K
Investor Ownership
History 		% of Portfolio Prev % Rank Conviction Avg Buy Price 13F Score™ 3Y / 7Y Sell Timing Shares Mkt Value Change Change % Source Quarter Filed

Frequently Asked Questions — Castle Biosciences Inc (CSTL)

What does the Smart Money Trend signal show for CSTL?

Selling streak — 1 quarter in a row: For 1 consecutive quarter, more hedge funds reduced or closed their CSTL positions than added to them. Sustained institutional selling is a meaningful warning sign — these are professionals with deep research teams collectively deciding to exit.

What is the institutional breadth score for CSTL?

Slight buying edge — 52% buying: Last quarter: 102 funds bought or added vs 95 that reduced or exited. It's nearly a 50/50 split — some institutions are convinced, others are taking profits. This mixed picture is normal near price highs.

What is the fund quality score for CSTL holders?

Strong quality — 29% AUM from major funds: 43 of 185 holders rank in the top 100 by AUM, accounting for 29% of total institutional value held. A meaningful share of the ownership value comes from the most well-resourced institutions.

How long have hedge funds held CSTL?

56% of holders stayed for 2+ years: 103 out of 185 hedge funds have held CSTL for over 2 years without selling. Long-term investors are generally harder to shake out during market stress, creating a stable ownership base that limits the risk of sudden capitulation.

Is it too late to buy Castle Biosciences Inc (CSTL) following the 2026 Q1 hedge fund 13F filings?

As of today, CSTL has moved +7.0% since the 2026 Q1 13F filing date (May 15, 2026), compared to +5.4% for the XLV sector ETF — an outperformance of +1.6%. Since the quarter end (March 31, 2026), CSTL has gained -16.7% vs +4.3% for XLV. The stock is tracking its sector benchmark closely. The signal remains fresh and the entry point is still near the fund's implied reference.

Where does this institutional ownership data come from?

All holdings data is sourced from SEC Form 13F filings, which institutional investment managers with over $100 million in assets are required to submit quarterly. Data is parsed directly from SEC EDGAR.

Disclaimer: The information on this page is for informational purposes only and does not constitute investment advice, a recommendation, or an offer to buy or sell any security. Institutional holdings data is sourced from SEC Form 13F filings and reflects positions as of the filing date. Past performance of any fund or portfolio is not indicative of future results. 13Foresight is not a registered investment adviser. Always conduct your own due diligence before making investment decisions.

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