Octagon Capital Advisors LP
Octagon Capital Advisors LP reported 26 US-listed holdings worth $1.09 billion in its 13F for the quarter ended 30 June 2026, filed 14 August 2026. Its largest: Dianthus Therapeutics Inc. (16.5%), Definium Therapeutics Inc. (12.7%) and Abivax SA (12.1%). Against the quarter before, it opened 4 positions, added to 4, trimmed 6 and sold out of 7.
The 14 largest of its 26 positions, each sized by its share of the reported holdings, coloured by the change in shares against Q1 2026.
What the fund reported holding at each quarter's end; hover a bar for the number of positions
What it did on the quarter
Its positions against its 13F for the quarter to 31 March 2026; a change under 0.1% of a position counts as held
Opened 4
- Summit Therapeutics Inc. SMMT$18.2 million
- Adlai Nortye Ltd ANL$10.7 million
- Sensei Biotherapeutics Inc. FTH$9.0 million
- Gyre Therapeutics Inc. GYRE$6.3 million
Added to 4
- Abivax SA ABVX+316,000 shares · +47%
- Definium Therapeutics Inc. DFTX+510,000 shares · +21%
- Pharvaris N V PHVS+291,721 shares · +177%
- Taysha Gene Therapies Inc. TSHA+833,333 shares · +9%
Trimmed 6
- Trevi Therapeutics Inc. TRVI-1.2 million shares · -79%
- Kymera Therapeutics Inc. KYMR-115,000 shares · -27%
- Ocular Therapeutix Inc. OCUL-1.1 million shares · -34%
- Dianthus Therapeutics Inc. DNTH-105,000 shares · -5%
- Precision Biosciences Inc. DTIL-886,732 shares · -40%
- Context Therapeutics Inc. CNTX-2.2 million shares · -42%
Sold out of 7
- Centessa Pharmaceuticals PLC CNTA$29.8 million last quarter
- Kalvista Pharmaceuticals Inc. KALV$29.2 million last quarter
- Terns Pharmaceuticals Inc. TERN$27.9 million last quarter
- Bridgebio Oncology Therapeutics Ord BBOT$6.4 million last quarter
- Lexeo Therapeutics Inc. LXEO$6.3 million last quarter
- Perspective Therapeutics Inc CATX$3.3 million last quarter
- Evommune Inc. EVMN$3.3 million last quarter
What it holds
| Company | Shares | Value | Of its book | Change in shares |
|---|---|---|---|---|
| Dianthus Therapeutics Inc. DNTH | 1,841,667 | $179.5 million | 16.48% | -105,000 |
| Definium Therapeutics Inc. DFTX | 2,950,000 | $138.8 million | 12.74% | +510,000 |
| Abivax SA ABVX | 993,000 | $132.3 million | 12.15% | +316,000 |
| Cogent Biosciences Inc. COGT | 2,350,000 | $90.9 million | 8.35% | no change |
| Alumis Inc. ALMS | 2,830,700 | $79.7 million | 7.31% | no change |
| Arrivent Biopharma Inc. AVBP | 1,971,054 | $68.5 million | 6.28% | no change |
| Taysha Gene Therapies Inc. TSHA | 9,693,244 | $66.0 million | 6.06% | +833,333 |
| Bioage Labs Inc. BIOA | 1,748,000 | $42.8 million | 3.93% | no change |
| Mirum Pharmaceuticals Inc. MIRM | 338,900 | $39.7 million | 3.64% | no change |
| Kymera Therapeutics Inc. KYMR | 310,000 | $35.5 million | 3.26% | -115,000 |
| Aktis Oncology Inc. AKTS | 960,847 | $31.0 million | 2.84% | no change |
| Xenon Pharmaceuticals Inc. XENE | 490,000 | $29.6 million | 2.71% | no change |
| Palisade Bio Inc. PALI | 10,276,317 | $21.5 million | 1.97% | no change |
| Ocular Therapeutix Inc. OCUL | 2,075,000 | $20.4 million | 1.87% | -1,091,600 |
| Disc Medicine Inc. IRON | 270,000 | $19.7 million | 1.81% | no change |
| Summit Therapeutics Inc. SMMT | 1,250,000 | $18.2 million | 1.67% | new |
| Pharvaris N V PHVS | 456,721 | $15.8 million | 1.45% | +291,721 |
| Adlai Nortye Ltd ANL | 934,716 | $10.7 million | 0.99% | new |
| Precision Biosciences Inc. DTIL | 1,350,000 | $10.6 million | 0.97% | -886,732 |
| DBV Technologies S A DBVT | 574,200 | $9.4 million | 0.86% | no change |
| Sensei Biotherapeutics Inc. FTH | 361,010 | $9.0 million | 0.83% | new |
| Gyre Therapeutics Inc. GYRE | 954,416 | $6.3 million | 0.58% | new |
| Trevi Therapeutics Inc. TRVI | 315,000 | $5.9 million | 0.54% | -1,170,000 |
| Unicycive Therapeutics Inc. UNCY | 1,000,000 | $4.7 million | 0.43% | no change |
| Context Therapeutics Inc. CNTX | 3,050,000 | $1.7 million | 0.16% | -2,200,000 |
| Gossamer Bio Inc. GOSS | 7,750,000 | $1.3 million | 0.12% | no change |
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Change is shares against its 13F for the quarter before; the 7 it sold out of are in the box above.Options it reported
| Company | Option | Shares under the options | Value of those shares |
|---|---|---|---|
| Erasca Inc. | Calls | 1,255,000 | $23.0 million |
1 option lines. A 13F lists calls and puts by the shares they cover and what those shares were worth at the quarter's end, not what the options cost; they are not counted in the holdings above.