Skip to main content

EcoR1 Capital, LLC

Location
San Francisco, CA
Portfolio Value
Mid $2,031,905,121
Diversification
Diversified
Filing Date
Global Rank
#1,165 / 7,976 ▲ 182
Top Industry
Biotechnology 96.3%
3Y Alpha vs SPY
-26.1%
Period ended 9 months ago
Filed Nov 14, 2025 · 7mo
23 quarters · since Mar 2020

Clone Performance

Jun 2023–Jun 2026 · vs SPY

Hypothetical growth of cloning every reported 13F position and rebalancing on each filing, indexed to the same start.

Cloned portfolio
-15.1%
SPY
+76.3%
Annualised alpha
-26.1%
Max drawdown
−62.6%

Estimate. 13F holdings are quarter-lagged and long-only, so the clone rebalances about 45 days after each period end — when the filing becomes public — and excludes options and short positions. Past performance does not predict future results.

Portfolio Concentration

26 positions · as of Sep 30, 2025 · Δ vs Jun 30, 2025
Top Position
19.3%
+0.1 pts
Top 5
62.5%
−2.2 pts
Top 10
82.7%
+0.3 pts
HHI
957
Dec 2022 → Sep 2025 · range 595 – 1,095
Diversified−34

Portfolio Trend

23 quarters · across all stocks

Sector Breakdown

As of Sep 30, 2025
Sector % Portfolio Value
Healthcare 100.0% $2,031,905,121

Last Quarter's Activity

Export CSV
Sep 30, 2025 vs Jun 30, 2025

Added To

Positions the filer increased
3 positions
Ticker Δ Shares Shares Value Open

Trimmed

Positions the filer reduced
4 positions
Ticker Δ Shares Shares Value Open

New Positions

Positions the filer opened this quarter
6 positions
Ticker Shares Value Open

Sold Out

Positions the filer fully exited
7 positions
Ticker Shares Value Open

Portfolio Positions

Export CSV View 13F filing
26 positions · $2,031,905,121 total · as of Sep 30, 2025
Ticker Company Shares Value (USD) % of Portfolio History