Group One Trading’s Castle Biosciences CSTL Stock Holding History

Group One Trading’s Portfolio CSTL Stock Details CSTL Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	–	Sell	-900	Closed	-$35K	–	7825
2025 Q4	$35K	Sell	900 -100	-10%	-$3.22K	﹤0.01%	5890
2025 Q3	$22.8K	Sell	1,000 -100	-9%	-$2.03K	﹤0.01%	6601
2025 Q2	$22.5K	Buy	1,100 +800	+267%	+$14.8K	﹤0.01%	6192
2025 Q1	$6.01K	Sell	300 -10,300	-97%	-$255K	﹤0.01%	6569
2024 Q4	$282K	Buy	10,600 +10,000	+1,667%	+$305K	﹤0.01%	3639
2024 Q3	$17.1K	Buy	+600	New	+$15.3K	﹤0.01%	5316
2023 Q3	–	Sell	-1,900	Closed	-$26.1K	–	7737
2023 Q2	$26.1K	Buy	+1,900	New	+$38.5K	﹤0.01%	5784
2022 Q4	–	Sell	-6,200	Closed	-$1.62M	–	7358
2022 Q3	$1.62M	Buy	+6,200	New	+$174K	﹤0.01%	2092
2021 Q3	–	Sell	-200	Closed	-$15K	–	8244
2021 Q2	$15K	Buy	+200	New	+$13.2K	﹤0.01%	7339

Other funds holding CSTL

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

RTW Investments New York $10B AUM 135.35% 1-Year Est. Return

Principal Financial Group Des Moines, Iowa $187B AUM 18.48% 1-Year Est. Return

PCM

Portolan Capital Management Boston, Massachusetts $1.88B AUM 115.74% 1-Year Est. Return

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

Dimensional Fund Advisors Austin, Texas $481B AUM 30.42% 1-Year Est. Return

SPPAM

Summit Partners Public Asset Management Boston, Massachusetts $3.72B AUM 162.29% 1-Year Est. Return

VPM

Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM

Allianz Asset Management Munich, Germany $95.4B AUM 38.74% 1-Year Est. Return

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

Group One Trading's CSTL Position: Q1 2026 in Review

Group One Trading opened a new position in Castle Biosciences (CSTL) in Q1 2026: 292 shares worth $7.17K. The stake represents ﹤0.01% of the portfolio and ranks #6546 among its holdings. This is a return to the name: Group One Trading previously reported a position in CSTL as recently as Q3 2025.

Group One Trading first reported a position in CSTL in Q3 2021 and has held it in 9 quarters since. The position peaked at $261K in Q4 2024. 186 funds tracked by Wall St. Rank hold CSTL as of Q1 2026.

Group One Trading held 292 shares of Castle Biosciences worth $7.17K as of Q1 2026.
Castle Biosciences was a new Group One Trading position in Q1 2026.
Castle Biosciences made up ﹤0.01% of Group One Trading's portfolio in Q1 2026, its #6546 holding.
Group One Trading first reported a position in Castle Biosciences in Q3 2021 and has held it in 9 quarters since.
Group One Trading's Castle Biosciences position peaked at $261K in Q4 2024.
186 funds tracked by Wall St. Rank held Castle Biosciences as of Q1 2026.

Based on Group One Trading's 13F filing for Q1 2026, filed 13 May 2026.