EC
TECX

EcoR1 Capital’s Tectonic Therapeutic TECX Stock Holding History

EcoR1 Capital’s Portfolio TECX Stock Details TECX Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2025
Q3 		– Sell
-935,121
Closed -$18.6M – 42
2025
Q2 		$18.6M Hold
935,121
– – 1.1% 20
2025
Q1 		$16.6M Buy
935,121
+85,978
+10% +$2.8M 0.98% 18
2024
Q4 		$39.2M Hold
849,143
– – 1.48% 16
2024
Q3 		$25.7M Hold
849,143
– – 0.88% 28
2024
Q2 		$14M Buy
+849,143
New +$13.6M 0.43% 40
2018
Q4 		– Sell
-5,721
Closed -$3.56M – 61
2018
Q3 		$3.56M Buy
+5,721
New +$2.54M 0.32% 40

Other funds holding TECX

Fidelity Investments
Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return
BlackRock
BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return
B
Braidwell Stamford, Connecticut $3B AUM 46.72% 1-Year Est. Return
FCM
Farallon Capital Management San Francisco, California $17.5B AUM 50.95% 1-Year Est. Return
Vanguard Group
Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return
5VM
5AM Venture Management San Francisco, California $360M AUM 345.76% 1-Year Est. Return
Point72 Asset Management
Point72 Asset Management Stamford, Connecticut $78.1B AUM 55.25% 1-Year Est. Return
PM
Prosight Management Dallas, Texas $610M AUM 40.86% 1-Year Est. Return
Aberdeen Group
Aberdeen Group Edinburgh, United Kingdom $61.9B AUM 29.81% 1-Year Est. Return
BG
Bollard Group Boston, Massachusetts $3.39B AUM 1.06% 1-Year Est. Return

EcoR1 Capital's TECX Position: Q3 2025 in Review

EcoR1 Capital sold out of Tectonic Therapeutic (TECX) in Q3 2025, closing a stake of 935,121 shares — an estimated $18.6M sold.

EcoR1 Capital first reported a position in TECX in Q3 2018 and held it in 6 quarters. The position peaked at $39.2M in Q4 2024. 99 funds tracked by Wall St. Rank hold TECX as of Q3 2025.

  • EcoR1 Capital reported no remaining Tectonic Therapeutic position as of Q3 2025 after selling out during the quarter.
  • EcoR1 Capital sold 935,121 Tectonic Therapeutic shares in Q3 2025, an estimated $18.6M.
  • EcoR1 Capital first reported a position in Tectonic Therapeutic in Q3 2018 and held it in 6 quarters.
  • EcoR1 Capital's Tectonic Therapeutic position peaked at $39.2M in Q4 2024.
  • 99 funds tracked by Wall St. Rank held Tectonic Therapeutic as of Q3 2025.

Based on EcoR1 Capital's 13F filing for Q3 2025, filed 14 Nov 2025.