EcoR1 Capital, LLC
13F Reported Value
ⓘ$2.4B
incl. option notional
Equity Holdings
ⓘ$2.3B
Option Notional
ⓘ$16.3M
$0 puts / $16.3M calls
Holdings
30
Latest Filing
2026-03-31
Filing Quarter
Q1 2026
Portfolio Overview
EcoR1 Capital, LLC disclosed 30 positions worth $2.4B in its Form 13F-HR for Q1 2026 — $2.3B in common stock plus $16.3M of put/call option positions (reported at underlying notional value, not premium at risk), led by $ZYME (Zymeworks Inc.) at 24.6% of the equity portfolio, followed by $ANAB and $JAZZ. During the quarter the fund opened 11 new positions and exited 11 — including a new stake in $AKTS and a full exit from $IMNM. The portfolio is most concentrated in Healthcare (97.8% of disclosed assets). All figures are sourced directly from EcoR1 Capital, LLC’s Form 13F-HR filing with the SEC under CIK 1587114.
AI Fund Analysis
ConcentratingSector Allocation
AUM History
Top Equity Holdings by Value
Option Positions
13F rules report options at the value of the underlying shares (notional) — not the premium paid or capital at risk. Shown separately from the equity sleeve above.
Quarterly Activity — Q1 2026
Click any card to unlockTop Holdings
- 27.2#2,475
Quality
$575.2M22,970,388 sh - 29.4#2,408
Quality
$437.0M7,880,094 sh - —
Quality
$322.6M1,706,469 sh - —
Quality
$238.3M6,000,000 sh - 26.5
Quality
$155.7M4,288,120 sh - —
Quality
$86.3M4,824,469 sh - —
Quality
$85.2M6,728,116 sh - 28.0
Quality
$74.6M1,102,000 sh - 4.5
Quality
$66.1M1,389,276 sh - 51.9
Quality
$53.6M2,171,938 sh
| Company | Quality | Value | Shares |
|---|---|---|---|
 Zymeworks Inc.$ZYME | 27.2#2,475 | $575.2M | 22,970,388 |
 ANAPTYSBIO, INC$ANAB | 29.4#2,408 | $437.0M | 7,880,094 |
 Jazz Pharmaceuticals plc$JAZZ | — | $322.6M | 1,706,469 |
 Centessa Pharmaceuticals plc$CNTA | — | $238.3M | 6,000,000 |
 Crinetics Pharmaceuticals, Inc.$CRNX | 26.5 | $155.7M | 4,288,120 |
 Aktis Oncology, Inc.$AKTS | — | $86.3M | 4,824,469 |
 Oric Pharmaceuticals, Inc.$ORIC | — | $85.2M | 6,728,116 |
 CG Oncology, Inc.$CGON | 28.0 | $74.6M | 1,102,000 |
 CRISPR Therapeutics AG$CRSP | 4.5 | $66.1M | 1,389,276 |
 Eton Pharmaceuticals, Inc.$ETON | 51.9 | $53.6M | 2,171,938 |
Unlock AI quality scores for every holding
32-signal composite ranking on each of EcoR1 Capital, LLC's 30 positions.
Showing top 10 of 30 holdings.
Sector Allocation
Healthcare
$2.3B
Other
$52.0M
Full Holdings — EcoR1 Capital, LLC (Q1 2026)
All 30 disclosed positions from the latest Form 13F-HR, with quarter-over-quarter share changes and 13F Pro quality scores. Sourced from SEC EDGAR.
| # | Ticker | Company | Value | Weight | QoQ | Quality |
|---|---|---|---|---|---|---|
| 1 | $ZYME | Zymeworks Inc. | $575.2M | 24.6% | +0% | 27.2 |
| 2 | $ANAB | ANAPTYSBIO, INC | $437.0M | 18.7% | +0% | 29.4 |
| 3 | $JAZZ | Jazz Pharmaceuticals plc | $322.6M | 13.8% | +0% | — |
| 4 | $CNTA | Centessa Pharmaceuticals plc | $238.3M | 10.2% | +93% | — |
| 5 | $CRNX | Crinetics Pharmaceuticals, Inc. | $155.7M | 6.7% | +0% | 26.5 |
| 6 | $AKTS | Aktis Oncology, Inc. | $86.3M | 3.7% | NEW | — |
| 7 | $ORIC | Oric Pharmaceuticals, Inc. | $85.2M | 3.6% | +0% | — |
| 8 | $CGON | CG Oncology, Inc. | $74.6M | 3.2% | +43% | 28 |
| 9 | $CRSP | CRISPR Therapeutics AG | $66.1M | 2.8% | +0% | 4.5 |
| 10 | $ETON | Eton Pharmaceuticals, Inc. | $53.6M | 2.3% | +7% | 51.9 |
| 11 | — | GALAPAGOS NV | $50.0M | 2.1% | +0% | — |
| 12 |  $XNCR | Xencor Inc | $26.3M | 1.1% | -33% | 13.1 |
| 13 |  $NGNE | Neurogene Inc. | $25.6M | 1.1% | +0% | — |
| 14 |  $BBOT | BridgeBio Oncology Therapeutics, Inc. | $25.3M | 1.1% | +0% | — |
| 15 |  $MBX | MBX Biosciences, Inc. | $23.2M | 1.0% | -63% | — |
| 16 |  $RLAY | Relay Therapeutics, Inc. | $19.0M | 0.8% | NEW | 12.7 |
| 17 | $CNTACALL | Centessa Pharmaceuticals plc | $16.3M | — | NEW | — |
| 18 |  $ZBIO | Zenas BioPharma, Inc. | $15.4M | 0.7% | +0% | 14.4 |
| 19 |  $ERAS | Erasca, Inc. | $14.6M | 0.6% | NEW | — |
| 20 |  $EIKN | Eikon Therapeutics, Inc. | $7.8M | 0.3% | NEW | — |
| 21 |  $REPL | Replimune Group, Inc. | $7.7M | 0.3% | NEW | — |
| 22 |  $ZURA | Zura Bio Ltd | $7.0M | 0.3% | NEW | — |
| 23 |  $PHAT | Phathom Pharmaceuticals, Inc. | $6.9M | 0.3% | NEW | 32.5 |
| 24 |  $MREO | Mereo BioPharma Group plc | $4.4M | 0.2% | +70% | — |
| 25 |  $STOK | Stoke Therapeutics, Inc. | $3.3M | 0.1% | NEW | 53.4 |
| 26 |  $PRLD | Prelude Therapeutics Inc | $3.2M | 0.1% | NEW | 27 |
| 27 |  $IBIO | iBio, Inc. | $3.0M | 0.1% | -29% | — |
| 28 | — | HELIX ACQUISITION CORP III USD | $2.0M | 0.1% | NEW | — |
| 29 |  $ATRA | Atara Biotherapeutics, Inc. | $471,075 | 0.0% | -83% | 63 |
| 30 |  $SRZN | Surrozen, Inc./DE | $129,454 | 0.0% | +0% | — |
New Positions (11)
$AKTS Aktis Oncology, Inc.$86.3M$RLAY Relay Therapeutics, Inc.$19.0M$CNTACALL Centessa Pharmaceuticals plc$16.3M$ERAS Erasca, Inc.$14.6M$EIKN Eikon Therapeutics, Inc.$7.8M$REPL Replimune Group, Inc.$7.7M$ZURA Zura Bio Ltd$7.0M$PHAT Phathom Pharmaceuticals, Inc.$6.9M$STOK Stoke Therapeutics, Inc.$3.3M$PRLD Prelude Therapeutics Inc$3.2M
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