Birchview Capital’s Castle Biosciences CSTL Stock Holding History

Birchview Capital’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	$317K	Sell	12,900 -67,700	-84%	-$2.22M	0.18%	60
2025 Q4	$3.14M	Sell	80,600 -30,000	-27%	-$967K	1.84%	17
2025 Q3	$2.52M	Hold	110,600	–	–	1.9%	13
2025 Q2	$2.26M	Buy	110,600 +22,196	+25%	+$411K	2.24%	12
2025 Q1	$1.77M	Buy	88,404 +10,404	+13%	+$258K	1.54%	19
2024 Q4	$2.08M	Buy	78,000 +20,000	+34%	+$609K	1.69%	18
2024 Q3	$1.65M	Buy	58,000 +24,000	+71%	+$611K	1.43%	20
2024 Q2	$740K	Buy	34,000 +20,000	+143%	+$446K	0.68%	24
2024 Q1	$310K	Buy	14,000 +4,000	+40%	+$87K	0.25%	47
2023 Q4	$216K	Buy	+10,000	New	+$176K	0.17%	51

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

Birchview Capital's CSTL Position: Q1 2026 in Review

Birchview Capital reduced its Castle Biosciences (CSTL) stake by 84% in Q1 2026, selling an estimated $2.22M and leaving 12,900 shares worth $317K. The position accounts for 0.18% of the portfolio, ranked #60.

Birchview Capital first reported a position in CSTL in Q4 2023 and has held it in 10 quarters since. The position peaked at $3.14M in Q4 2025. 186 funds tracked by Wall St. Rank hold CSTL as of Q1 2026.

Birchview Capital held 12,900 shares of Castle Biosciences worth $317K as of Q1 2026.
Birchview Capital sold 67,700 Castle Biosciences shares in Q1 2026, an estimated $2.22M.
Castle Biosciences made up 0.18% of Birchview Capital's portfolio in Q1 2026, its #60 holding.
Birchview Capital first reported a position in Castle Biosciences in Q4 2023 and has held it in 10 quarters since.
Birchview Capital's Castle Biosciences position peaked at $3.14M in Q4 2025.
186 funds tracked by Wall St. Rank held Castle Biosciences as of Q1 2026.

Based on Birchview Capital's 13F filing for Q1 2026, filed 15 May 2026.