DEERFIELD MANAGEMENT COMPANY, L.P. — Quarter-over-Quarter 13F Allocation Shifts Q1 2026
In Q1 2026, DEERFIELD MANAGEMENT COMPANY, L.P. initiated 10 new positions, increased allocation to 10 existing positions, trimmed 9 positions, and exited 79 positions entirely. The fund's 13F equity book grew from $7.80B to $8.48B (+8.7% QoQ) . All deltas are sourced from sequential SEC Form 13F-HR filings; share-count changes reflect explicit trading activity, while weight changes can also include price movement. This page lists every position change reported — the portfolio overview shows a summary of the top shifts.
Net Portfolio Value Change
- $7.80BPrior quarter
- $8.48BCurrent quarter
- + $0.68BNet delta
- +8.7%% change
New Position Initiations Q1 2026
Securities disclosed for the first time in Q1 2026 that were not present in the prior 13F-HR filing.
| Company | Ticker | Initial Allocation Weight | History |
|---|---|---|---|
| INDIVIOR PHARMACEUTICALS INC | INDV | 1.11% | Holders → |
| SYNDAX PHARMACEUTICALS | SNDX | 1.04% | Holders → |
| DIANTHUS THERAPEUTICS INC | DNTH | 1.01% | Holders → |
| PFIZER INC | PFE | 1.01% | Holders → |
| GENMAB A/S | GMAB | 0.78% | Holders → |
| BIOMARIN PHARMACEUTICALS | BMRN | 0.57% | Holders → |
| TYRA BIOSCIENCES INC | TYRA | 0.25% | Holders → |
| BRIGHT MINDS BIOSCIENCES INC | DRUG | 0.24% | Holders → |
| SPYGLASS PHARMA INC | SGP | 0.17% | Holders → |
| VERADERMICS INC | MANE | 0.00% | Holders → |
Largest Allocation Increases Q1 2026
Largest portfolio-weight increases in existing positions. Share-count delta is shown separately so price-only re-weighting can be distinguished from active adds.
| Company | Ticker | Δ Weight | Δ Shares | History |
|---|---|---|---|---|
| XENON PHARMACEUTICALS INC | XENE | +0.80% | +198.09% | Holders → |
| MONOPAR THERAPEUTICS INC | MNPR | +0.07% | +89.82% | Holders → |
| INSPIRE MEDICAL SYSTEMS INC | INSP | +-0.14% | +79.51% | Holders → |
| IP STRATEGY HOLDINGS INC | UNKNOWN | +3.59% | +46.10% | History → |
| TANGO THERAPEUTICS INC | TNGX | +0.69% | +42.65% | Holders → |
| BETA BIONICS INC | BBNX | +-0.21% | +41.11% | Holders → |
| BELITE BIO INC | BLTE | +0.09% | +30.02% | Holders → |
| LEGEND BIOTECH CORP | LEGN | +-0.01% | +29.60% | Holders → |
| DISC MEDICINE INC | IRON | +-0.02% | +28.53% | Holders → |
| FOGHORN THERAPEUTICS INC | FHTX | +-0.00% | +20.42% | Holders → |
Largest Allocation Reductions Q1 2026
Largest portfolio-weight decreases in existing positions (positions kept open at a lower allocation).
| Company | Ticker | Δ Weight | Δ Shares | History |
|---|---|---|---|---|
| NEUROCRINE BIOSCIENCES INC | NBIX | -1.21% | -48.49% | Holders → |
| IDEAYA BIOSCIENCES, INC. | IDYA | -0.35% | -28.94% | Holders → |
| REVOLUTION MEDICINES INC | RVMD | -0.32% | -20.65% | History → |
| CATALYST PHARMACEUTICALS INC | CPRX | -0.32% | -19.70% | Holders → |
| ARROWHEAD PHARMACEUTICALS INC | ARWR | -0.40% | -14.17% | Holders → |
| VERA THERAPEUTICS INC | VERA | -0.87% | -8.32% | Holders → |
| CENTENE CORP | CNC | -1.12% | -8.23% | History → |
| EMBECTA CORPORATION | EMBC | -0.15% | -7.89% | Holders → |
| ENVISTA HOLDINGS CORPORATION | NVST | 0.03% | -3.09% | Holders → |
Exited Positions Q1 2026
Positions present in the prior 13F-HR filing that no longer appear in Q1 2026.
Methodology & FAQ
How DEERFIELD MANAGEMENT COMPANY, L.P. Quarterly Changes Are Computed
Each row above is computed by joining the most recent 13F-HR filing for DEERFIELD MANAGEMENT COMPANY, L.P. against the immediately preceding quarterly filing for the same fund. Portfolio weights are normalized to exclude listed options for comparability. A complete description of the methodology — including how confidential treatment filings are handled and why share count rather than weight is the cleaner trading signal — is documented in the Methodology.
Which positions did DEERFIELD MANAGEMENT COMPANY, L.P. initiate in Q1 2026?
DEERFIELD MANAGEMENT COMPANY, L.P. established 10 new positions in Q1 2026: INDIVIOR PHARMACEUTICALS INC (INDV, 1.11%), SYNDAX PHARMACEUTICALS (SNDX, 1.04%), DIANTHUS THERAPEUTICS INC (DNTH, 1.01%), PFIZER INC (PFE, 1.01%), GENMAB A/S (GMAB, 0.78%), BIOMARIN PHARMACEUTICALS (BMRN, 0.57%), TYRA BIOSCIENCES INC (TYRA, 0.25%), BRIGHT MINDS BIOSCIENCES INC (DRUG, 0.24%), SPYGLASS PHARMA INC (SGP, 0.17%), VERADERMICS INC (MANE, 0.00%).
Which existing positions saw the largest allocation increases for DEERFIELD MANAGEMENT COMPANY, L.P. in Q1 2026?
The largest portfolio-weight increases in existing positions were: XENON PHARMACEUTICALS INC (XENE, +0.80% weight, +198.09% shares), MONOPAR THERAPEUTICS INC (MNPR, +0.07% weight, +89.82% shares), INSPIRE MEDICAL SYSTEMS INC (INSP, +-0.14% weight, +79.51% shares), IP STRATEGY HOLDINGS INC (UNKNOWN, +3.59% weight, +46.10% shares), TANGO THERAPEUTICS INC (TNGX, +0.69% weight, +42.65% shares), BETA BIONICS INC (BBNX, +-0.21% weight, +41.11% shares), BELITE BIO INC (BLTE, +0.09% weight, +30.02% shares), LEGEND BIOTECH CORP (LEGN, +-0.01% weight, +29.60% shares), DISC MEDICINE INC (IRON, +-0.02% weight, +28.53% shares), FOGHORN THERAPEUTICS INC (FHTX, +-0.00% weight, +20.42% shares).
Which positions did DEERFIELD MANAGEMENT COMPANY, L.P. fully exit in Q1 2026?
DEERFIELD MANAGEMENT COMPANY, L.P. fully exited 79 positions in Q1 2026: INDIVIOR PLC (SYN_G4766E116, last-reported weight 1.56%), PHREESIA INC (PHR, last-reported weight 0.43%), LANTHEUS HLDGS INC (SYN_516544AB9, last-reported weight 0.37%), VENTAS INC (VTR, last-reported weight 0.35%), SPYRE THERAPEUTICS, INC. (SYRE, last-reported weight 0.30%), EDGEWISE THERAPEUTICS, INC. (EWTX, last-reported weight 0.24%), CORMEDIX INC (CRMD, last-reported weight 0.17%), MEDLINE INC (MDLN, last-reported weight 0.14%), OMADA HEALTH INC (OMDA, last-reported weight 0.11%), CALCIMEDICA INC (CALC, last-reported weight 0.11%), PRESTIGE CONSMR HEALTHCARE (PBH, last-reported weight 0.06%), VEEVA SYSTEMS (VEEV, last-reported weight 0.05%), RADNET INC (RDNT, last-reported weight 0.05%), LABCORP HOLDINGS INC (LH, last-reported weight 0.04%), ENOVIS CORPORATION (ENOV, last-reported weight 0.04%), ALIGNMENT HEALTHCARE INC (ALHC, last-reported weight 0.04%), QUEST DIAGNOSTICS INC (DGX, last-reported weight 0.04%), TRANSMEDICS GROUP INC (TMDX, last-reported weight 0.04%), INSULET CORP (PODD, last-reported weight 0.04%), BIOLIFE SOLUTIONS INC (BLFS, last-reported weight 0.04%), CHEMED CORP NEW (CHE, last-reported weight 0.03%), PETCO HEALTH & WELLNESS CO I (WOOF, last-reported weight 0.03%), ORTHOPEDIATRICS CORP (KIDS, last-reported weight 0.03%), THE CIGNA GROUP (CI, last-reported weight 0.03%), TRUPANION INC (TRUP, last-reported weight 0.03%), RESMED INC (RMD, last-reported weight 0.03%), BOSTON SCIENTIFIC CORP (BSX, last-reported weight 0.03%), DAVITA, INC (DVA, last-reported weight 0.03%), DOXIMITY INC (DOCS, last-reported weight 0.03%), DEXCOM INC (DXCM, last-reported weight 0.03%), IRHYTHM HOLDINGS INC (IRTC, last-reported weight 0.03%), CONMED CORP (CNMD, last-reported weight 0.03%), MASIMO CORP (MASI, last-reported weight 0.03%), LEMAITRE VASCULAR INC (LMAT, last-reported weight 0.03%), 10X GENOMICS INC (TXG, last-reported weight 0.03%), ATRICURE INC (ATRC, last-reported weight 0.03%), AVANOS MED INC (AVNS, last-reported weight 0.02%), CORVEL CORP (CRVL, last-reported weight 0.02%), CARDINAL HEALTH INC (CAH, last-reported weight 0.02%), GOODRX HLDGS INC (GDRX, last-reported weight 0.02%), SURGERY PARTNERS INC (SGRY, last-reported weight 0.02%), ALIGN TECHNOLOGY INC (ALGN, last-reported weight 0.02%), ADDUS HOMECARE CORP (ADUS, last-reported weight 0.02%), MERIT MED SYS INC (MMSI, last-reported weight 0.02%), NATIONAL HEALTHCARE CORP (NHC, last-reported weight 0.02%), ENCOMPASS HEALTH CORP (EHC, last-reported weight 0.02%), VAREX IMAGING CORP (VREX, last-reported weight 0.02%), HEALTHEQUITY INC (HQY, last-reported weight 0.02%), ABBOTT LABS (ABT, last-reported weight 0.02%), MAXIMUS INC (MMS, last-reported weight 0.02%), STRYKER CORPORATION (SYK, last-reported weight 0.02%), ALPHATEC HLDGS INC (ATEC, last-reported weight 0.02%), STAAR SURGICAL CO (STAA, last-reported weight 0.02%), UFP TECHNOLOGIES INC (UFPT, last-reported weight 0.01%), KENVUE, INC. (KVUE, last-reported weight 0.01%), MIMEDX GROUP INC (MDXG, last-reported weight 0.01%), INTEGER HLDGS CORP (ITGR, last-reported weight 0.01%), REVVITY INC (RVTY, last-reported weight 0.01%), AZENTA INC (AZTA, last-reported weight 0.01%), ARVINAS INC (ARVN, last-reported weight 0.01%), ZOETIS INC (ZTS, last-reported weight 0.01%), COOPER COMPANIES (COO, last-reported weight 0.01%), SCHRODINGER INC (SDGR, last-reported weight 0.01%), TANDEM DIABETES CARE INC (TNDM, last-reported weight 0.01%), RXSIGHT INC (RXST, last-reported weight 0.01%), INTEGRA LIFESCIENCES HLDGS C (IART, last-reported weight 0.01%), ABBVIE INC (ABBV, last-reported weight 0.01%), HARROW INC (HROW, last-reported weight 0.01%), XERIS BIOPHARMA HOLDINGS INC (XERS, last-reported weight 0.01%), HEALTHCARE SVCS GROUP INC (HCSG, last-reported weight 0.01%), AMPHASTAR PHARMACEUTICALS IN (AMPH, last-reported weight 0.01%), REPLIGEN CORP (RGEN, last-reported weight 0.00%), STERIS PLC (STE, last-reported weight 0.00%), BELLRING BRANDS, INC. (BRBR, last-reported weight 0.00%), INTUITIVE SURGICAL, INC. (ISRG, last-reported weight 0.00%), NATIONAL VISION HLDGS INC (EYE, last-reported weight 0.00%), ABEONA THERAPEUTICS INC (ABEO, last-reported weight 0.00%), NUVATION BIO INC (SYN_67080N119, last-reported weight 0.00%), BUTTERFLY NETWORK INC (BFLYW, last-reported weight 0.00%).
Which existing positions saw the largest allocation reductions for DEERFIELD MANAGEMENT COMPANY, L.P. in Q1 2026?
The largest portfolio-weight reductions in positions kept open were: NEUROCRINE BIOSCIENCES INC (NBIX, -1.21% weight, -48.49% shares), IDEAYA BIOSCIENCES, INC. (IDYA, -0.35% weight, -28.94% shares), REVOLUTION MEDICINES INC (RVMD, -0.32% weight, -20.65% shares), CATALYST PHARMACEUTICALS INC (CPRX, -0.32% weight, -19.70% shares), ARROWHEAD PHARMACEUTICALS INC (ARWR, -0.40% weight, -14.17% shares), VERA THERAPEUTICS INC (VERA, -0.87% weight, -8.32% shares), CENTENE CORP (CNC, -1.12% weight, -8.23% shares), EMBECTA CORPORATION (EMBC, -0.15% weight, -7.89% shares), ENVISTA HOLDINGS CORPORATION (NVST, 0.03% weight, -3.09% 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.