Octagon Capital Advisors LP — 13F Holdings & Portfolio
CIK 1839435 · latest 13F-HR filed 2026-08-14
Octagon Capital Advisors LP manages $1.11B in 13F-reported U.S. long-equity assets across 27 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are DNTH (16.14%), DFTX (12.47%), ABVX (11.89%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 4 new positions and exited 7; 12 existing positions rose in reported value and 7 fell.
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.
Long-equity book
Distinct positions
Filed 2026-08-14
vs 2026-03-31
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
Portfolio map
Q2 26Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.
Sector mix
% of 13F valueSectors from each company's SIC code; funds and ETFs grouped separately.
Biggest buys and sells
Q1 26 → Q2 26Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.
13F assets and positions
4 quartersTotal reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.
Top positions over time
reported valueThe eight largest current positions, valued at each quarter end.
Concentration
top 10 = 80.2%Cumulative share of the portfolio held in the largest N positions.
As of the firm’s regulatory filing dated Mar 20, 2026.
NEW YORK, NY 10065
| Name | Title / Status | Ownership | Type |
|---|---|---|---|
| HIRSCH, JUSTIN, M Control | CHIEF COMPLIANCE OFFICER AND CHIEF FINANCIAL OFFICER since Nov 2019 | Less than 5% | Individual |
| JIA, TING, (NMN) Control | FOUNDER, PORTFOLIO MANAGER, AND LIMITED PARTNER since Nov 2019 | 75% or more | Individual |
| OCTAGON CAPITAL ADVISORS, LLC Control | GENERAL PARTNER since Nov 2019 | Less than 5% | Domestic Entity |
| JIA, TING, (NMN) Control Indirect owner via OCTAGON CAPITAL ADVISORS, LLC | MANAGING MEMBER since Nov 2019 | 75% or more | Individual |
Ownership & leadership changes · 2 filings with changes since Nov 8, 2019
From the firm’s regulatory filings, newest first. Dates are filing dates: a filing that no longer lists someone does not say when they left.
- AddedJIA, TING, (NMN) · MANAGING MEMBER · 75% or more · indirect via OCTAGON CAPITAL ADVISORS, LLC · control person
- ChangedJIA, TING, (NMN) · title FOUNDER AND PORTFOLIO MANAGER → FOUNDER, PORTFOLIO MANAGER, AND LIMITED PARTNER
- AddedOCTAGON CAPITAL ADVISORS, LLC · GENERAL PARTNER · Less than 5% · control person
- ListedHIRSCH, JUSTIN, M · CHIEF COMPLIANCE OFFICER AND CHIEF FINANCIAL OFFICER · Less than 5% · control person
- ListedJIA, TING, (NMN) · FOUNDER AND PORTFOLIO MANAGER · 75% or more · control person
Quarter-over-quarter changes
Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.
Top Adds (vs prior quarter)
- DEFINIUM THERAPEUTICS INC$92.7M +200.9%
- ABIVAX SA$56.9M +75.5%
- TAYSHA GENE THERAPIES INC$26.4M +66.7%
- ARRIVENT BIOPHARMA INC$23.0M +50.6%
- ALUMIS INC$17.3M +27.7%
Top Trims
- CONTEXT THERAPEUTICS INC-$12.1M -87.7%
- TREVI THERAPEUTICS INC-$11.8M -66.8%
- OCULAR THERAPEUTIX INC-$6.4M -24.0%
- DBV TECHNOLOGIES S A-$2.6M -21.5%
- UNICYCIVE THERAPEUTICS INC-$1.9M -28.7%
New Positions
- SUMMIT THERAPEUTICS INC$18.2M
- ADLAI NORTYE LTD$10.7M
- FAETH THERAPEUTICS INC$9.0M
- GYRE THERAPEUTICS INC$6.3M
Exited Positions
- CENTESSA PHARMACEUTICALS PLC$29.8M
- KALVISTA PHARMACEUTICALS INC$29.2M
- TERNS PHARMACEUTICALS INC$27.9M
- BRIDGEBIO ONCOLOGY THERAPEUT$6.4M
- LEXEO THERAPEUTICS INC$6.3M
Octagon Capital Advisors LP Holdings (2026-06-30)
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 | $179.5M | 16.14% | 1,841,667 | SH |
| 2 | DEFINIUM THERAPEUTICS INC | DFTX | 24477V105 | $138.8M | 12.47% | 2,950,000 | SH |
| 3 | ABIVAX SA | ABVX | 00370M103 | $132.3M | 11.89% | 993,000 | SH |
| 4 | COGENT BIOSCIENCES INC | COGT | 19240Q201 | $90.9M | 8.17% | 2,350,000 | SH |
| 5 | ALUMIS INC | ALMS | 022307102 | $79.7M | 7.16% | 2,830,700 | SH |
| 6 | ARRIVENT BIOPHARMA INC | AVBP | 04272N102 | $68.5M | 6.15% | 1,971,054 | SH |
| 7 | TAYSHA GENE THERAPIES INC | TSHA | 877619106 | $66.0M | 5.93% | 9,693,244 | SH |
| 8 | BIOAGE LABS INC | BIOA | 09077V100 | $42.8M | 3.85% | 1,748,000 | SH |
| 9 | MIRUM PHARMACEUTICALS INC | MIRM | 604749101 | $39.7M | 3.57% | 338,900 | SH |
| 10 | KYMERA THERAPEUTICS INC | KYMR | 501575104 | $35.5M | 3.20% | 310,000 | SH |
| 11 | AKTIS ONCOLOGY INC | AKTS | 01021M104 | $31.0M | 2.78% | 960,847 | SH |
| 12 | XENON PHARMACEUTICALS INC | XENE | 98420N105 | $29.6M | 2.66% | 490,000 | SH |
| 13 | ERASCA INC Call | ERAS | 29479A908 | $23.0M | 2.07% | 1,255,000 | SH |
| 14 | PALISADE BIO INC | PALI | 696389402 | $21.5M | 1.93% | 10,276,317 | SH |
| 15 | OCULAR THERAPEUTIX INC | OCUL | 67576A100 | $20.4M | 1.83% | 2,075,000 | SH |
| 16 | DISC MEDICINE INC | IRON | 254604101 | $19.7M | 1.78% | 270,000 | SH |
| 17 | SUMMIT THERAPEUTICS INC | SMMT | 86627T108 | $18.2M | 1.64% | 1,250,000 | SH |
| 18 | PHARVARIS N V | PHVS | N69605108 | $15.8M | 1.42% | 456,721 | SH |
| 19 | ADLAI NORTYE LTD | ANL | 00704R109 | $10.7M | 0.97% | 934,716 | SH |
| 20 | PRECISION BIOSCIENCES INC | DTIL | 74019P207 | $10.6M | 0.95% | 1,350,000 | SH |
| 21 | DBV TECHNOLOGIES S A | DBVT | 23306J309 | $9.4M | 0.85% | 574,200 | SH |
| 22 | FAETH THERAPEUTICS INC | FTH | 81728A207 | $9.0M | 0.81% | 361,010 | SH |
| 23 | GYRE THERAPEUTICS INC | GYRE | 403783103 | $6.3M | 0.57% | 954,416 | SH |
| 24 | TREVI THERAPEUTICS INC | TRVI | 89532M101 | $5.9M | 0.53% | 315,000 | SH |
| 25 | UNICYCIVE THERAPEUTICS INC | UNCY | 90466Y202 | $4.7M | 0.42% | 1,000,000 | SH |
| 26 | CONTEXT THERAPEUTICS INC | CNTX | 21077P108 | $1.7M | 0.15% | 3,050,000 | SH |
| 27 | GOSSAMER BIO INC | GOSS | 38341P102 | $1.3M | 0.11% | 7,750,000 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-14 | $1.11B | 27 | 0001839435-26-000004 |
| 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 |
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NEW YORK, NY 10065