Institutional
EcoR1 Capital, LLC
CIK 0001587114
$2.36B
Reported AUM
29
Positions
Q1 2026
Period
2026-05-15
Filed
The Brief · EcoR1 Capital, LLC · Q1 2026
AI · grounded in 13F
EcoR1 Capital, LLC closed its position in IMNM for a reduction of $61.3M. The fund established a new position in AKTS worth $86.3M and increased its stake in CNTA by 105.8%. Other notable activity includes new positions in RLAY and ERAS, alongside the closure of positions in GPCR and PCVX.
Portfolio · Q1 2026
Top holdings
| # | Stock | Issuer | Price | Day % | 1Y Gr. | 5Y Gr. | Value | % of book | Δ shares (QoQ) | Status |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | ZYME | ZYMEWORKS INC | $22.71 | 3.18% | 80.67% | -31.16% | $575.2M | 24.41% | — | HELD |
| 2 | ANAB | ANAPTYSBIO INC | $55.04 | 5.56% | 224.54% | 212.89% | $437.0M | 18.55% | — | HELD |
| 3 | JAZZ | JAZZ PHARMACEUTICALS PLC | $258.38 | 0.94% | 122.16% | 94.86% | $322.6M | 13.69% | — | HELD |
| 4 | CNTA | CENTESSA PHARMACEUTICALS PLC | — | — | 0.00% | — | $254.6M | 10.81% | — | HELD |
| 5 | CRNX | CRINETICS PHARMACEUTICALS IN | $83.63 | -0.30% | 201.02% | 255.56% | $155.7M | 6.61% | — | HELD |
| 6 | AKTS | AKTIS ONCOLOGY INC | $23.00 | 2.72% | 2.68% | 14.26% | $86.3M | 3.66% | — | HELD |
| 7 | ORIC | ORIC PHARMACEUTICALS INC | $11.64 | 3.19% | 15.02% | -47.31% | $85.2M | 3.62% | — | HELD |
| 8 | CGON | CG ONCOLOGY INC | $73.03 | 5.66% | 168.57% | 58.04% | $74.6M | 3.17% | — | HELD |
| 9 | CRSP | CRISPR THERAPEUTICS AG | $48.44 | 1.68% | -15.07% | -61.87% | $66.1M | 2.80% | — | HELD |
| 10 | ETON | ETON PHARMACEUTICALS INC | $49.03 | 1.87% | 240.55% | 813.09% | $53.6M | 2.27% | — | HELD |
| 11 | LKFT | GALAPAGOS NV | $27.64 | -0.29% | -15.26% | -52.87% | $50.0M | 2.12% | — | HELD |
| 12 | XNCR | XENCOR INC | $21.49 | 10.04% | 169.30% | -36.55% | $26.3M | 1.12% | — | HELD |
| 13 | NGNE | NEUROGENE INC | $33.60 | -0.18% | 54.11% | -79.41% | $25.6M | 1.09% | — | HELD |
| 14 | BBOT | BRIDGEBIO ONCOLOGY THERAPEUT | $8.50 | 3.22% | -19.45% | -19.18% | $25.3M | 1.07% | — | HELD |
| 15 | MBX | MBX BIOSCIENCES INC | $66.46 | 3.91% | 378.44% | 187.27% | $23.2M | 0.98% | — | HELD |
| 16 | RLAY | RELAY THERAPEUTICS INC | $19.45 | 5.88% | 461.61% | -41.09% | $19.0M | 0.80% | — | HELD |
| 17 | ZBIO | ZENAS BIOPHARMA INC | $32.27 | 3.80% | 101.75% | 46.41% | $15.4M | 0.66% | — | HELD |
| 18 | ERAS | ERASCA INC | $18.68 | 5.42% | 1243.88% | -21.87% | $14.6M | 0.62% | — | HELD |
| 19 | EIKN | EIKON THERAPEUTICS INC | $9.62 | 6.77% | -33.66% | -9.07% | $7.8M | 0.33% | — | HELD |
| 20 | REPL | REPLIMUNE GROUP INC | — | — | -28.82% | -82.97% | $7.7M | 0.32% | — | HELD |
| 21 | ZURA | ZURA BIO LTD | $5.54 | 4.33% | 272.67% | -17.91% | $7.0M | 0.30% | — | HELD |
| 22 | PHAT | PHATHOM PHARMACEUTICALS INC | $9.03 | -22.42% | 39.40% | -67.29% | $6.9M | 0.29% | — | HELD |
| 23 | MREO | MEREO BIOPHARMA GROUP PLC | $0.31 | 2.61% | -81.54% | -89.01% | $4.4M | 0.19% | — | HELD |
| 24 | STOK | STOKE THERAPEUTICS INC | $30.04 | 1.90% | 132.69% | 14.74% | $3.3M | 0.14% | — | HELD |
| 25 | PRLD | PRELUDE THERAPEUTICS INC | $5.05 | 7.22% | 509.90% | -85.85% | $3.2M | 0.14% | — | HELD |
| 26 | IBIO | IBIO INC | $1.39 | 2.21% | 110.61% | -99.78% | $3.0M | 0.13% | — | HELD |
| 27 | HLXC | HELIX ACQUISITION CORP III USD | $10.51 | 0.00% | 2.54% | 2.14% | $2.0M | 0.09% | — | HELD |
| 28 | ATRA | ATARA BIOTHERAPEUTICS INC | $8.17 | 1.36% | -29.26% | -97.82% | $471K | 0.02% | — | HELD |
| 29 | SRZNW | SURROZEN INC | — | — | -30.59% | — | $129K | 0.01% | — | HELD |
Source: SEC EDGAR · accession 0000935836-26-000270. 13F discloses long positions only — shorts, foreign equities, and options are excluded.