Stocks/Funds/CIK 1587114

EcoR1 Capital, LLC

long-term holder
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1587114
Assets
$2.34B
+39.2% YoY
Holdings
29
Lifetime alpha vs market
-17.96% annual
Average hold time
2.5 yr
median 1.8 yr

Quarterly history

Cum return -31% vs S&P +52% · α -83% lifetimeAUM $2.3B · peak $3.9BFlow $30M (+1%)2016-062017-122019-062020-122022-062023-122025-062026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
-0.91%
trims when stocks drop
when a holding falls −10%+
Middle response
-2.72%
baseline attrition
Rally response
-1.45%
trims into rallies
when a holding rises +10%+

Top positions · 29

Ticker$ value% portYoYHold time
$575M24.6%3.5 yr
ANABAnaptysBio, Inc.$437M18.7%+198.4%6.5 yr
JAZZJazz Pharmaceuticals plc$323M13.8%+52.3%3.0 yr
CNTACentessa Pharmaceuticals$238M10.2%+176.2%4.3 yr
CRNXCrinetics Pharmaceutical$156M6.7%+8.3%5.0 yr
AKTSAktis Oncology, Inc.$86M3.7%0.3 yr
ORICORIC Pharmaceuticals, In$85M3.6%+127.1%6.0 yr
CGONCG Oncology, Inc. Common$75M3.2%+176.4%0.5 yr
CRSPCRISPR Therapeutics AG$66M2.8%+39.8%3.8 yr
ETONEton Pharmaceuticals, In$54M2.3%+90.1%1.8 yr
GLPGGalapagos N.V.$50M2.1%+19.4%7.3 yr
XNCRXencor, Inc.$26M1.1%+13.3%8.8 yr
NGNENeurogene Inc.$26M1.1%+72.2%2.5 yr
BBOTBridgeBio Oncology Thera$25M1.1%0.8 yr
MBXMBX Biosciences, Inc. Co$23M1.0%+304.5%1.8 yr

Portfolio composition (YoY)

Industry mix
Biotechnology74.9%-12.7pp$1.75B
Unknown25.0%+12.6pp$585M
Shell Companies0.1%$2M
Country
US45.8%-14.3pp
Unknown25.0%+12.6pp
IE13.8%-7.3pp
GB10.4%+9.6pp
CH2.8%+0.0pp
BE2.1%+1.9pp
KY0.1%
Top 5: 73.9% · Top 10: 89.5% · Top 25: 99.8%

Winners

TickerPrev $PnLYoY %
ANAB$146M+0.19B198.4%
JAZZ$212M+0.11B52.3%
MBX$9M+0.03B304.5%
ORIC$19M+0.02B127.1%
ETON$25M+0.02B90.1%

Losers

TickerPrev $PnLYoY %
REPL$8M-0.00B-21.5%
0HIY.L$3M-0.00B-26.1%

Top buys this quarter · 13

CNTA Centessa Pharmaceuticals plc+$115M
AKTS Aktis Oncology, Inc.new+$86M
CGON CG Oncology, Inc. Common stock+$22M
RLAY Relay Therapeutics, Inc.+$13M
EIKN Eikon Therapeutics, Inc. Commonew+$8M
PHAT Phathom Pharmaceuticals, Inc.+$5M
ERAS Erasca, Inc.+$4M
ETON Eton Pharmaceuticals, Inc.+$3M
STOK Stoke Therapeutics, Inc.new+$3M
HLXC Helix Acquisition Corp. III Clnew+$2M

Top sells this quarter · 13

IMNM Immunome, Inc.exit$62M
MBX MBX Biosciences, Inc. Common S$40M
PCVX Vaxcyte, Inc.exit$26M
GPCR Structure Therapeutics Inc.exit$16M
VYGR Voyager Therapeutics, Inc.exit$15M
XNCR Xencor, Inc.$13M
AQST Aquestive Therapeutics, Inc.exit$11M
MNKD MannKind Corporationexit$4M
EOLS Evolus, Inc.exit$3M
0HIY.L Atara Biotherapeutics, Inc.$2M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$2.34B29+62.43%+17.59%+44.84%+0.03B
2025-12-31$2.18B27+10.42%+17.72%-7.30%-0.09B
2025-09-30$2.08B29-11.12%+17.52%-28.64%-0.41B
2025-06-30$1.68B34-40.30%+14.94%-55.25%+0.08B
2025-03-31$1.68B42-49.71%+8.30%-58.01%-0.11B
2024-12-31$2.50B53-26.33%+24.89%-51.22%-0.07B
2024-09-30$2.92B61-5.07%+36.04%-41.11%-0.32B
2024-06-30$3.27B53-24.97%+24.49%-49.46%+0.11B
2024-03-31$3.93B55+1.51%+29.62%-28.11%-0.12B
2023-12-31$3.85B48-14.11%+26.18%-40.29%+0.52B
2023-09-30$2.93B46-30.72%+21.57%-52.28%-0.03B
2023-06-30$3.79B47+7.21%+19.42%-12.21%+0.43B
2023-03-31$3.10B53-16.87%-7.82%-9.05%+0.18B
2022-12-31$3.28B61-8.55%+7.56%-16.11%+0.19B
2022-09-30$3.38B70+21.15%-4.93%+26.08%-0.10B
2022-06-30$2.87B72-15.85%-16.11%+0.26%+0.19B