Octagon Capital Advisors LP — 13F Holdings & Portfolio
CIK 1839435 · latest 13F-HR filed 2026-05-15
Octagon Capital Advisors LP manages $903.6M in 13F-reported U.S. long-equity assets across 29 reported positions as of its 2026-03-31 13F-HR filing. Its largest disclosed positions are DNTH (18.08%), COGT (10.01%), ABVX (8.34%). Quarter over quarter (versus its 2025-12-31 filing) the fund opened 8 new positions, exited 5, added to 10, and trimmed 11.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
$903.6M
Long-equity book
29
Distinct positions
2026-03-31
Filed 2026-05-15
+8 / −5 / ↑10 / ↓11
vs 2025-12-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- DIANTHUS THERAPEUTICS INC$63.8M +64.0%
- ALUMIS INC$37.7M +152.5%
- CENTESSA PHARMACEUTICALS PLC$11.0M +58.8%
- BIOAGE LABS INC$9.4M +44.6%
- KALVISTA PHARMACEUTICALS INC$8.6M +41.9%
Top Trims
- GOSSAMER BIO INC-$40.6M -94.1%
- ABIVAX SA-$26.6M -26.1%
- TREVI THERAPEUTICS INC-$17.5M -49.7%
- PHARVARIS N V-$14.0M -75.0%
- LEXEO THERAPEUTICS INC-$10.8M -63.1%
New Positions
- DEFINIUM THERAPEUTICS INC$46.1M
- MIRUM PHARMACEUTICALS INC$31.3M
- XENON PHARMACEUTICALS INC$28.5M
- TERNS PHARMACEUTICALS INC$27.9M
- DISC MEDICINE INC$17.3M
Exited Positions
- MIND MEDICINE MINDMED INC$29.9M
- CIDARA THERAPEUTICS INC$22.1M
- RAPT THERAPEUTICS INC$19.4M
- CORBUS PHARMACEUTICALS HLDGS$7.8M
- PEPGEN INC$4.6M
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | DIANTHUS THERAPEUTICS INC | DNTH | 252828108 | $163.4M | 18.08% | 1,946,667 | SH |
| 2 | COGENT BIOSCIENCES INC | COGT | 19240Q201 | $90.5M | 10.01% | 2,350,000 | SH |
| 3 | ABIVAX SA | ABVX | 00370M103 | $75.4M | 8.34% | 677,000 | SH |
| 4 | ALUMIS INC | ALMS | 022307102 | $62.4M | 6.90% | 2,830,700 | SH |
| 5 | DEFINIUM THERAPEUTICS INC | DFTX | 24477V105 | $46.1M | 5.10% | 2,440,000 | SH |
| 6 | ARRIVENT BIOPHARMA INC | AVBP | 04272N102 | $45.5M | 5.03% | 1,971,054 | SH |
| 7 | TAYSHA GENE THERAPIES INC | TSHA | 877619106 | $39.6M | 4.38% | 8,859,911 | SH |
| 8 | KYMERA THERAPEUTICS INC | KYMR | 501575104 | $35.4M | 3.92% | 425,000 | SH |
| 9 | MIRUM PHARMACEUTICALS INC | MIRM | 604749101 | $31.3M | 3.46% | 338,900 | SH |
| 10 | BIOAGE LABS INC | BIOA | 09077V100 | $30.6M | 3.38% | 1,748,000 | SH |
| 11 | CENTESSA PHARMACEUTICALS PLC | CNTA | 152309100 | $29.8M | 3.30% | 750,000 | SH |
| 12 | KALVISTA PHARMACEUTICALS INC | KALV | 483497103 | $29.2M | 3.23% | 1,450,000 | SH |
| 13 | XENON PHARMACEUTICALS INC | XENE | 98420N105 | $28.5M | 3.15% | 490,000 | SH |
| 14 | TERNS PHARMACEUTICALS INC | TERN | 880881107 | $27.9M | 3.09% | 530,000 | SH |
| 15 | OCULAR THERAPEUTIX INC | OCUL | 67576A100 | $26.8M | 2.97% | 3,166,600 | SH |
| 16 | PALISADE BIO INC | PALI | 696389402 | $18.0M | 1.99% | 10,276,317 | SH |
| 17 | TREVI THERAPEUTICS INC | TRVI | 89532M101 | $17.7M | 1.96% | 1,485,000 | SH |
| 18 | DISC MEDICINE INC | IRON | 254604101 | $17.3M | 1.91% | 270,000 | SH |
| 19 | AKTIS ONCOLOGY INC | AKTS | 01021M104 | $17.2M | 1.90% | 960,847 | SH |
| 20 | CONTEXT THERAPEUTICS INC | CNTX | 21077P108 | $13.8M | 1.52% | 5,250,000 | SH |
| 21 | PRECISION BIOSCIENCES INC | DTIL | 74019P207 | $12.3M | 1.36% | 2,236,732 | SH |
| 22 | DBV TECHNOLOGIES S A | DBVT | 23306J309 | $12.0M | 1.33% | 574,200 | SH |
| 23 | UNICYCIVE THERAPEUTICS INC | UNCY | 90466Y202 | $6.6M | 0.73% | 1,000,000 | SH |
| 24 | BRIDGEBIO ONCOLOGY THERAPEUT | BBOT | 107924102 | $6.4M | 0.71% | 719,000 | SH |
| 25 | LEXEO THERAPEUTICS INC | LXEO | 52886X107 | $6.3M | 0.70% | 1,100,000 | SH |
| 26 | PHARVARIS N V | PHVS | N69605108 | $4.7M | 0.52% | 165,000 | SH |
| 27 | PERSPECTIVE THERAPEUTICS INC | CATX | 46489V302 | $3.3M | 0.37% | 791,555 | SH |
| 28 | EVOMMUNE INC | EVMN | 30054Y107 | $3.3M | 0.37% | 143,472 | SH |
| 29 | GOSSAMER BIO INC | GOSS | 38341P102 | $2.5M | 0.28% | 7,750,000 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-15 | $903.6M | 29 | 0001839435-26-000003 |
| 2025-12-31 | 2026-02-17 | $823.7M | 27 | 0001839435-26-000002 |
| 2025-09-30 | 2025-11-14 | $659.8M | 27 | 0001839435-25-000010 |