Octagon Capital Advisors LP 13F: Quarter-over-Quarter Portfolio Changes
Octagon Capital Advisors LP reported a disclosed portfolio value of approximately $903.6 million in its latest SEC Form 13F-HR filing for Q1 2026, up 13.1% quarter on quarter. Over the quarter, the fund initiated 8 new positions, bought more shares in 6 holdings, trimmed 9 holdings, and exited 5 positions.
Octagon Capital Advisors LP's top buy was a new stake in Definium Therapeutics INC (DFTX) , equal to 5.1% of the disclosed portfolio. Its top sell was Mind Medicine Mindmed INC (BRD1EUR) . The fund exited the position completely after it had accounted for 3.7% of the previous portfolio.
New PositionsQ1 2026
Securities disclosed for the first time in Q1 2026 that were not present in the prior 13F-HR filing.
| Company | Ticker | Initial Portfolio Weight | History |
|---|---|---|---|
| DEFINIUM THERAPEUTICS INC | DFTX | 5.1% | History → |
| MIRUM PHARMACEUTICALS INC | MIRM | 3.5% | History → |
| XENON PHARMACEUTICALS INC | XENE | 3.2% | Holders → |
| TERNS PHARMACEUTICALS INC | TERN | 3.1% | Holders → |
| DISC MEDICINE INC | IRON | 1.9% | Holders → |
| AKTIS ONCOLOGY INC | AKTS | 1.9% | Holders → |
| CONTEXT THERAPEUTICS INC | CNTX | 1.5% | Holders → |
| PERSPECTIVE THERAPEUTICS | CATX | 0.4% | Holders → |
Top BuysQ1 2026
The fund's top buys among existing positions in Q1 2026. Ranked by portfolio-weight impact, with the percentage of additional shares shown separately.
| Company | Ticker | Portfolio Weight Change | More Shares | History |
|---|---|---|---|---|
| OCULAR THERAPEUTIX INC | OCUL | +-1.0% | +20.7% | Holders → |
| PRECISION BIOSCIENCES INC | DTIL | +0.4% | +16.6% | Holders → |
| KALVISTA PHARMACEUTICALS | KALV | +0.7% | +13.9% | Holders → |
| ALUMIS INC | ALMS | +3.8% | +11.9% | History → |
| BIOAGE LABS INC | BIOA | +0.7% | +9.4% | History → |
| PALISADE BIO INC | PALI | +-0.8% | +7.4% | Holders → |
Top SellsQ1 2026
The fund's top sells among positions it retained in Q1 2026. Ranked by portfolio-weight impact. Full exits are listed separately.
| Company | Ticker | Portfolio Weight Change | Shares Sold | History |
|---|---|---|---|---|
| PHARVARIS N V | PHVS | -1.8% | 75.4% | Holders → |
| EVOMMUNE INC | EVMN | -0.7% | 71.3% | Holders → |
| TREVI THERAPEUTICS INC | TRVI | -2.5% | 47.2% | Holders → |
| GOSSAMER BIO INC | GOSS | -5.1% | 44.3% | Holders → |
| LEXEO THERAPEUTICS INC | LXEO | -1.4% | 36.2% | Holders → |
| BRIDGEBIO ONCOLOGY THERAPEUT | BBOT | -0.9% | 31.1% | Holders → |
| KYMERA THERAPEUTICS INC | KYMR | -1.3% | 20.6% | History → |
| DIANTHUS THERAPEUTICS IN | DNTH | 5.6% | 19.4% | History → |
| ABIVAX SA | ABVX | -4.4% | 10.4% | History → |
Full ExitsQ1 2026
Positions present in the prior 13F-HR filing that no longer appear in Q1 2026.
| Company | Ticker | Last-Reported Portfolio Weight |
|---|---|---|
| MIND MEDICINE MINDMED INC | BRD1EUR | 3.7% |
| CIDARA THERAPEUTICS INC | CDTX | 2.8% |
| RAPT THERAPEUTICS INC | RAPT | 2.4% |
| CORBUS PHARMACEUTICALS HLDGS | CRBP | 1.0% |
| PEPGEN INC | PEPG | 0.6% |
Net Portfolio Value ChangeQ1 2026
- $0.8BPrior quarter
- $0.9BCurrent quarter
- +$0.1BNet delta
- +13.1%% change
Methodology & FAQ
How Octagon Capital Advisors LP Quarterly Changes Are Computed
All deltas are sourced from sequential SEC Form 13F-HR filings for Octagon Capital Advisors LP: each row joins the most recent filing against the immediately preceding quarterly filing for the same fund. Share-count changes reflect reported trading activity, while portfolio weights can also move because of market price changes. Portfolio weights are normalized to exclude listed options for comparability. A complete description — including how confidential treatment filings are handled — is documented in the Methodology.
What stocks did Octagon Capital Advisors LP buy in Q1 2026?
In Q1 2026, Octagon Capital Advisors LP initiated 8 new positions (DEFINIUM THERAPEUTICS INC (DFTX), MIRUM PHARMACEUTICALS INC (MIRM), XENON PHARMACEUTICALS INC (XENE), TERNS PHARMACEUTICALS INC (TERN), DISC MEDICINE INC (IRON), AKTIS ONCOLOGY INC (AKTS), CONTEXT THERAPEUTICS INC (CNTX), PERSPECTIVE THERAPEUTICS (CATX)); bought more shares of OCULAR THERAPEUTIX INC (OCUL), PRECISION BIOSCIENCES INC (DTIL), KALVISTA PHARMACEUTICALS (KALV), ALUMIS INC (ALMS), BIOAGE LABS INC (BIOA) — the largest 5 of 6 adds.
What stocks did Octagon Capital Advisors LP sell in Q1 2026?
In Q1 2026, Octagon Capital Advisors LP fully sold 5 positions (MIND MEDICINE MINDMED INC (BRD1EUR), CIDARA THERAPEUTICS INC (CDTX), RAPT THERAPEUTICS INC (RAPT), CORBUS PHARMACEUTICALS HLDGS (CRBP), PEPGEN INC (PEPG)); reduced holdings in PHARVARIS N V (PHVS), EVOMMUNE INC (EVMN), TREVI THERAPEUTICS INC (TRVI), GOSSAMER BIO INC (GOSS), LEXEO THERAPEUTICS INC (LXEO) — the largest 5 of 9 reductions.
Which positions did Octagon Capital Advisors LP initiate in Q1 2026?
Octagon Capital Advisors LP established 8 new positions in Q1 2026: DEFINIUM THERAPEUTICS INC (DFTX, 5.1%), MIRUM PHARMACEUTICALS INC (MIRM, 3.5%), XENON PHARMACEUTICALS INC (XENE, 3.2%), TERNS PHARMACEUTICALS INC (TERN, 3.1%), DISC MEDICINE INC (IRON, 1.9%), AKTIS ONCOLOGY INC (AKTS, 1.9%), CONTEXT THERAPEUTICS INC (CNTX, 1.5%), PERSPECTIVE THERAPEUTICS (CATX, 0.4%).
Which existing positions saw the largest allocation increases for Octagon Capital Advisors LP in Q1 2026?
Of 6 existing positions with share-count increases in Q1 2026, the largest were: OCULAR THERAPEUTIX INC (OCUL, +-1.0% weight, +20.7% shares), PRECISION BIOSCIENCES INC (DTIL, +0.4% weight, +16.6% shares), KALVISTA PHARMACEUTICALS (KALV, +0.7% weight, +13.9% shares), ALUMIS INC (ALMS, +3.8% weight, +11.9% shares), BIOAGE LABS INC (BIOA, +0.7% weight, +9.4% shares), PALISADE BIO INC (PALI, +-0.8% weight, +7.4% shares).
Which positions did Octagon Capital Advisors LP fully exit in Q1 2026?
Octagon Capital Advisors LP fully exited 5 positions in Q1 2026: MIND MEDICINE MINDMED INC (BRD1EUR, last-reported weight 3.7%), CIDARA THERAPEUTICS INC (CDTX, last-reported weight 2.8%), RAPT THERAPEUTICS INC (RAPT, last-reported weight 2.4%), CORBUS PHARMACEUTICALS HLDGS (CRBP, last-reported weight 1.0%), PEPGEN INC (PEPG, last-reported weight 0.6%).
Which existing positions saw the largest allocation reductions for Octagon Capital Advisors LP in Q1 2026?
Of 9 existing positions with share-count reductions in Q1 2026, the largest were: PHARVARIS N V (PHVS, -1.8% weight, -75.4% shares), EVOMMUNE INC (EVMN, -0.7% weight, -71.3% shares), TREVI THERAPEUTICS INC (TRVI, -2.5% weight, -47.2% shares), GOSSAMER BIO INC (GOSS, -5.1% weight, -44.3% shares), LEXEO THERAPEUTICS INC (LXEO, -1.4% weight, -36.2% shares), BRIDGEBIO ONCOLOGY THERAPEUT (BBOT, -0.9% weight, -31.1% shares), KYMERA THERAPEUTICS INC (KYMR, -1.3% weight, -20.6% shares), DIANTHUS THERAPEUTICS IN (DNTH, 5.6% weight, -19.4% shares), ABIVAX SA (ABVX, -4.4% weight, -10.4% shares).
Do quarter-over-quarter 13F allocation changes constitute explicit trading signals?
No. Quarter-over-quarter changes reflect a combination of active trading and market price movement. A weight increase can result from price appreciation alone, without the manager adding shares. Share-count delta is the cleaner indicator of explicit trading activity. All deltas on this page are sourced from sequential SEC Form 13F-HR filings.