Arkolith/Funds/EcoR1 Capital, LLC

EcoR1 Capital, LLC

CIK: 1587114Q1 2026
Active Filer
Portfolio Value
$2.4B
Positions
39
New Buys
10
9 sold
Changes
5 ↑ / 4 ↓

Top HoldingsQ1 2026

39 total positions
#SecurityValueShares% PortChangeΔ Shares
1ZYMEWORKS INC
COM
$575.2M22.97M24.4%
HELD
0
2ANAPTYSBIO INC
COM
$437.0M7.88M18.5%
HELD
0
3
JAZZ PHARMACEUTICALS PLC
SHS USD
$322.6M1.71M13.7%
HELD
0
4CENTESSA PHARMACEUTICALS PLC
SPONSORED ADS
$238.3M6.00M10.1%
ADDED
+2.88M
5CRINETICS PHARMACEUTICALS IN
COM
$155.7M4.29M6.6%
HELD
0
6AKTIS ONCOLOGY INC
COM ADDED
$86.3M4.82M3.7%
NEW
7ORIC PHARMACEUTICALS INC
COM
$85.2M6.73M3.6%
HELD
0
8CG ONCOLOGY INC
COM
$74.6M1.10M3.2%
ADDED
+809.2K
9
CRISPR THERAPEUTICS AG
NAMEN AKT
$66.1M1.39M2.8%
HELD
0
10ETON PHARMACEUTICALS INC
COM
$53.6M2.17M2.3%
ADDED
+141.4K
11GALAPAGOS NV
SPON ADR
$50.0M1.67M2.1%
HELD
0
12XENCOR INC
COM
$26.3M2.18M1.1%
ADDED
+2.12M
13NEUROGENE INC
COM
$25.6M1.27M1.1%
HELD
0
14BRIDGEBIO ONCOLOGY THERAPEUT
COM NEW
$25.3M2.82M1.1%
HELD
0
15MBX BIOSCIENCES INC
COM
$23.2M777.0K1.0%
REDUCED
-1,346,604
16RELAY THERAPEUTICS INC
COM
$19.0M1.90M0.8%
NEW
17CENTESSA PHARMACEUTICALS PLC
SPONSORED ADS
$16.3M410.8K0.7%
REDUCED
-2,704,200
18ZENAS BIOPHARMA INC
COM
$15.4M789.5K0.7%
HELD
0
19ERASCA INC
COM
$14.6M900.0K0.6%
NEW
20EIKON THERAPEUTICS INC
COM ADDED
$7.8M732.6K0.3%
NEW
21REPLIMUNE GROUP INC
COM
$7.7M1.00M0.3%
NEW
22
ZURA BIO LTD
CLASS A ORD SHS
$7.0M1.18M0.3%
NEW
23PHATHOM PHARMACEUTICALS INC
COM
$6.9M625.0K0.3%
NEW
24MEREO BIOPHARMA GROUP PLC
SPON ADS
$4.4M13.37M0.2%
ADDED
+5.51M
25STOKE THERAPEUTICS INC
COM
$3.3M100.0K0.1%
NEW
Showing top 25 of 39 positions

Filing History

Q1 202630 pos
$2.4B
Q4 202530 pos
$2.2B

Data Source

Holdings data sourced from SEC EDGAR 13F-HR filings. Updated quarterly, approximately 45 days after quarter end. All data is public domain.

Last filed: May 15, 2026