Portolan Capital Management, LLC Castle Biosciences Inc Transaction History

Portolan Capital Management, LLC

$1.38 Billion
Q2 2025

A detailed history of Portolan Capital Management, LLC transactions in Castle Biosciences Inc stock. As of the latest transaction made, Portolan Capital Management, LLC holds 1,489,572 shares of CSTL stock, worth $28.8 Million. This represents 2.2% of its overall portfolio holdings.

Number of Shares

1,489,572

Previous 1,265,223 17.73%

Holding current value

$28.8 Million

Previous $25.3 Million 20.09%

% of portfolio

2.2%

Previous 2.07%

22 transactions

Quarter	Operation	Price Per share	shares change	shares Held
Q2 2025 Aug 13, 2025	BUY	$15.8 - $21.98 $3.54 Million - $4.93 Million	224,349 Added 17.73%	1,489,572 $30.4 Million
Q1 2025 May 15, 2025	BUY	$18.76 - $32.72 $9.17 Million - $16 Million	488,644 Added 62.92%	1,265,223 $25.3 Million
Q4 2024 Feb 13, 2025	SELL	$26.52 - $34.67 $12.7 Million - $16.6 Million	-479,049 Reduced 38.15%	776,579 $20.7 Million
Q3 2024 Nov 14, 2024	BUY	$17.4 - $31.47 $777,362 - $1.41 Million	44,676 Added 3.69%	1,255,628 $35.8 Million
Q2 2024 Aug 14, 2024	BUY	$18.84 - $24.94 $3.16 Million - $4.18 Million	167,542 Added 16.06%	1,210,952 $26.4 Million
Q1 2024 May 15, 2024	BUY	$18.06 - $25.3 $5.68 Million - $7.96 Million	314,757 Added 43.2%	1,043,410 $23.1 Million
Q4 2023 Feb 14, 2024	BUY	$12.19 - $22.43 $5.8 Million - $10.7 Million	475,625 Added 187.97%	728,653 $15.7 Million
Q3 2023 Nov 14, 2023	SELL	$13.28 - $20.3 $2.37 Million - $3.62 Million	-178,446 Reduced 41.36%	253,028 $4.27 Million
Q2 2023 Aug 14, 2023	BUY	$11.66 - $26.0 $2.04 Million - $4.55 Million	174,825 Added 68.12%	431,474 $5.92 Million
Q1 2023 May 15, 2023	SELL	$19.47 - $28.49 $6.37 Million - $9.32 Million	-327,067 Reduced 56.03%	256,649 $5.83 Million
Q4 2022 Feb 13, 2023	BUY	$18.08 - $30.0 $5.12 Million - $8.49 Million	283,126 Added 94.19%	583,716 $13.7 Million
Q3 2022 Nov 14, 2022	BUY	$22.51 - $34.32 $3.28 Million - $5 Million	145,622 Added 93.97%	300,590 $7.84 Million
Q2 2022 Aug 15, 2022	BUY	$16.0 - $45.99 $2.48 Million - $7.13 Million	154,968 New	154,968 $3.4 Million
Q3 2021 Nov 15, 2021	SELL	$60.13 - $77.6 $548,806 - $708,255	-9,127 Closed	0 $0
Q2 2021 Aug 16, 2021	BUY	$50.07 - $76.78 $456,988 - $700,771	9,127 New	9,127 $669,000
Q1 2021 May 17, 2021	SELL	$58.92 - $97.33 $976,481 - $1.61 Million	-16,573 Closed	0 $0
Q4 2020 Feb 16, 2021	SELL	$43.6 - $73.05 $482,172 - $807,859	-11,059 Reduced 40.02%	16,573 $1.11 Million
Q3 2020 Nov 16, 2020	SELL	$38.47 - $52.03 $1.7 Million - $2.3 Million	-44,202 Reduced 61.53%	27,632 $1.42 Million
Q2 2020 Aug 14, 2020	SELL	$27.28 - $43.01 $1.74 Million - $2.74 Million	-63,820 Reduced 47.05%	71,834 $2.71 Million
Q1 2020 May 14, 2020	SELL	$23.08 - $35.53 $3.92 Million - $6.04 Million	-169,924 Reduced 55.61%	135,654 $4.04 Million
Q4 2019 Feb 14, 2020	BUY	$15.74 - $35.04 $2.84 Million - $6.33 Million	180,647 Added 144.6%	305,578 $10.5 Million
Q3 2019 Nov 14, 2019	BUY	$18.09 - $27.92 $2.26 Million - $3.49 Million	124,931 New	124,931 $2.26 Million

Others Institutions Holding CSTL

# of Institutions

168

Shares Held

26.9M

Call Options Held

Put Options Held

View Full List

About CASTLE BIOSCIENCES INC

Ticker CSTL
Exchange NASDAQ
Sector Healthcare
Industry Diagnostics & Research
Shares Outstandng 26,297,000
Market Cap $509M
Description
Castle Biosciences, Inc., a commercial-stage diagnostics company, focuses to provide diagnostic and prognostic testing services for dermatological cancers. Its lead product is DecisionDx-Melanoma, a multi-gene expression profile (GEP) test to identify the risk of metastasis for patients diagnosed with invasive cutaneous melanoma. The company als...

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Portolan Capital Management, LLC Castle Biosciences Inc Transaction History