Siren LLC’s Centessa Pharmaceuticals CNTA Stock Holding History

Siren LLC’s Portfolio CNTA Stock Details CNTA Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$41.8M	Sell	1,053,464 -2,974,053	-74%	-$76.1M	1.16%	23
2025 Q4	$101M	Buy	4,027,517 +800,000	+25%	+$20.3M	3%	6
2025 Q3	$78.3M	Sell	3,227,517 -232,512	-7%	-$4.13M	3.06%	6
2025 Q2	$45.5M	Buy	3,460,029 +500,000	+17%	+$6.33M	2.35%	8
2025 Q1	$42.6M	Sell	2,960,029 -44,648	-1%	-$731K	2.4%	12
2024 Q4	$50.3M	Sell	3,004,677 -254,000	-8%	-$4.21M	2.22%	11
2024 Q3	$52.1M	Buy	+3,258,677	New	+$39.9M	2.6%	11

Other funds holding CNTA

MVM

Medicxi Ventures Management St. Helier, Jersey $177M AUM 212.06% 1-Year Est. Return

ACA

Avoro Capital Advisors New York $10.2B AUM 149.19% 1-Year Est. Return

IVLAV

Index Venture Life Associates VI St. Helier, Jersey $396M AUM 176.22% 1-Year Est. Return

Adage Capital Partners Boston, Massachusetts $64.8B AUM 42.7% 1-Year Est. Return

PCM

Pentwater Capital Management Naples, Florida $19.3B AUM 58.13% 1-Year Est. Return

Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

EcoR1 Capital San Francisco, California $2.36B AUM 204.53% 1-Year Est. Return

Perceptive Advisors New York $5.12B AUM 314.02% 1-Year Est. Return

Capital World Investors Los Angeles, California $846B AUM 46.74% 1-Year Est. Return

FCM

Farallon Capital Management San Francisco, California $17.5B AUM 50.95% 1-Year Est. Return

Siren LLC's CNTA Position: Q1 2026 in Review

Siren LLC reduced its Centessa Pharmaceuticals (CNTA) stake by 74% in Q1 2026, selling an estimated $76.1M and leaving 1,053,464 shares worth $41.8M. The position accounts for 1.16% of the portfolio, ranked #23.

Siren LLC first reported a position in CNTA in Q3 2024 and has held it in 7 quarters since. The position peaked at $101M in Q4 2025. 161 funds tracked by Wall St. Rank hold CNTA as of Q1 2026.

Siren LLC held 1,053,464 shares of Centessa Pharmaceuticals worth $41.8M as of Q1 2026.
Siren LLC sold 2,974,053 Centessa Pharmaceuticals shares in Q1 2026, an estimated $76.1M.
Centessa Pharmaceuticals made up 1.16% of Siren LLC's portfolio in Q1 2026, its #23 holding.
Siren LLC first reported a position in Centessa Pharmaceuticals in Q3 2024 and has held it in 7 quarters since.
Siren LLC's Centessa Pharmaceuticals position peaked at $101M in Q4 2025.
161 funds tracked by Wall St. Rank held Centessa Pharmaceuticals as of Q1 2026.

Based on Siren LLC's 13F filing for Q1 2026, filed 14 May 2026.