Rock Springs Capital Management LP
Baltimore, MD
$2.0bn in 104 US stocks at the end of 30 June 2026. The top 10 are 44.0% of the money. It changed about 19.8% of the portfolio this quarter.
Value
$2.0bn
Stocks
104
Top 10 share
44.0%
Turnover
19.8%
What changed this quarter
New
Bought for the first time this quarter.
- Ascendis Pharma A/SASND2.2% of the fund
- Avalyn PharmaAVLN1.1% of the fund
- Hemab Therapeutics HoldingsCOAG1.0% of the fund
- Parabilis MedicinesPBLS0.8% of the fund
- OmerosOMER0.3% of the fund
- Definium TherapeuticsDFTX0.3% of the fund
- Mobia MedicalMOBI0.3% of the fund
- Trevi TherapeuticsTRVI0.2% of the fund
- Spyre TherapeuticsSYRE0.2% of the fund
- Nervgen PharmaNGEN0.1% of the fund
- MedtronicMDT0.1% of the fund
- Sagimet BiosciencesSGMT<0.1% of the fund
- Capricor TherapeuticsCAPR<0.1% of the fund
- AltimmuneALT<0.1% of the fund
- Kailera TherapeuticsKLRA<0.1% of the fund
- Axsome TherapeuticsAXSM<0.1% of the fund
- GlaukosGKOS<0.1% of the fund
Added
Bought more of a stock they already held.
- Travere TherapeuticsTVTX6.0% of the fund+47%
- Madrigal PharmaceuticalsMDGL4.6% of the fund+2%
- InsmedINSM1.9% of the fund+15%
- iRhythm HoldingsIRTC1.6% of the fund+3%
- UnitedHealth GroupUNH1.3% of the fund+20%
- Celldex TherapeuticsCLDX1.3% of the fund+8%
- ErascaERAS1.3% of the fund+27%
- MiniMed GroupMMED1.1% of the fund+44%
- Boston ScientificBSX1.1% of the fund+3%
- Tarsus PharmaceuticalsTARS0.9% of the fund+23%
- MBX BiosciencesMBX0.8% of the fund+4%
- CytokineticsCYTK0.8% of the fund+314%
- Bicara TherapeuticsBCAX0.8% of the fund+9%
- DanaherDHR0.7% of the fund+24%
- Tango TherapeuticsTNGX0.7% of the fund+18%
- Mineralys TherapeuticsMLYS0.6% of the fund+10%
- Inspire Medical SystemsINSP0.5% of the fund+85%
- BridgeBio PharmaBBIO0.5% of the fund+13%
- Alkermes plc.ALKS0.5% of the fund+9%
- Indivior PharmaceuticalsINDV0.5% of the fund+23%
- StrykerSYK0.4% of the fund+96%
- Compass TherapeuticsCMPX0.4% of the fund+7%
- PhreesiaPHR0.4% of the fund+16%
- Corcept TherapeuticsCORT0.3% of the fund+43%
- EyePointEYPT0.2% of the fund+4%
Cut
Sold some of their stake.
- Revolution MedicinesRVMD10.1% of the fund-9%
- Kymera TherapeuticsKYMR2.5% of the fund-9%
- Argenx SEARGX2.4% of the fund-46%
- Xenon PharmaceuticalsXENE2.0% of the fund-10%
- Scholar Rock HoldingSRRK1.9% of the fund-3%
- PenumbraPEN1.8% of the fund-4%
- Ultragenyx PharmaceuticalRARE1.6% of the fund-21%
- Intuitive SurgicalISRG1.5% of the fund-7%
- Neurocrine BiosciencesNBIX1.2% of the fund-4%
- Enliven TherapeuticsELVN1.2% of the fund-44%
- DexcomDXCM1.1% of the fund-4%
- Aclaris TherapeuticsACRS1.1% of the fund-3%
- Dyne TherapeuticsDYN1.0% of the fund-3%
- Alnylam PharmaceuticalsALNY1.0% of the fund-10%
- Cogent BiosciencesCOGT1.0% of the fund-17%
- Agios PharmaceuticalsAGIO1.0% of the fund-33%
- Vera TherapeuticsVERA0.9% of the fund-15%
- Evolent HealthEVH0.7% of the fund-7%
- ArdelyxARDX0.6% of the fund-3%
- AzentaAZTA0.5% of the fund-29%
- Caris Life SciencesCAI0.4% of the fund-13%
- Omada HealthOMDA0.4% of the fund-31%
- Novo Nordisk A SNVO0.1% of the fund-29%
- Dianthus TherapeuticsDNTH<0.1% of the fund-24%
- Surgery PartnersSGRY<0.1% of the fund-60%
Sold out
Sold their entire stake.
- Ascendis Pharma A/SASND-100%
- Arcellx-100%
- Centessa Pharmaceuticals-100%
- Soleno Therapeutics-100%
- Regeneron PharmaceuticalsREGN-100%
- Apellis Pharmaceuticals-100%
- Terns Pharmaceuticals-100%
- Spdr Series TrustXBI-100%
- Edwards LifesciencesEW-100%
- Acadia Healthcare CompanyACHC-100%
- Jazz PharmaceuticalsJAZZ-100%
- Gossamer BioGOSS-100%
- Amicus Therapeutics-100%
Holdings
- Argenx SEARGX
- Share
- 2.4%
- Value
- $49m
- Shares
- 52,750
-46%
- Structure TherapeuticsGPCR
- Share
- 1.7%
- Value
- $34m
- Shares
- 640,317
Held
- Avalyn PharmaAVLN
- Share
- 1.1%
- Value
- $22m
- Shares
- 662,918
New
- Hemab Therapeutics HoldingsCOAG
- Share
- 1.0%
- Value
- $21m
- Shares
- 575,432
New
- Parabilis MedicinesPBLS
- Share
- 0.8%
- Value
- $16m
- Shares
- 578,028
New
- ZAI LABZLAB
- Share
- 0.8%
- Value
- $15m
- Shares
- 814,707
Held
- Edap TMS S AFOCL
- Share
- 0.4%
- Value
- $7m
- Shares
- 1,386,000
Held
- Mobia MedicalMOBI
- Share
- 0.3%
- Value
- $6m
- Shares
- 418,200
New
- Nervgen PharmaNGEN
- Share
- 0.1%
- Value
- $2m
- Shares
- 1,208,231
New
- Kailera TherapeuticsKLRA
- Share
- <0.1%
- Value
- $1m
- Shares
- 65,000
New
- Legend BiotechLEGN
- Share
- <0.1%
- Value
- $967,480
- Shares
- 33,500
-17%
| Company | Share of fund | Value | Shares | Change |
|---|---|---|---|---|
| Revolution MedicinesRVMD | 10.1% | $207m | 1,105,210 | -9% |
| Travere TherapeuticsTVTX | 6.0% | $124m | 2,179,069 | +47% |
| Eli LillyLLY | 5.8% | $118m | 98,700 | Held |
| Madrigal PharmaceuticalsMDGL | 4.6% | $94m | 174,999 | +2% |
| Mirum PharmaceuticalsMIRM | 4.6% | $93m | 798,145 | Held |
| Rhythm PharmaceuticalsRYTM | 3.8% | $77m | 692,598 | Held |
| Kymera TherapeuticsKYMR | 2.5% | $52m | 453,156 | -9% |
| Argenx SEARGX | 2.4% | $49m | 52,750 | -46% |
| Ascendis Pharma A/SASND | 2.2% | $45m | 168,750 | New |
| Xenon PharmaceuticalsXENE | 2.0% | $41m | 683,907 | -10% |
| Scholar Rock HoldingSRRK | 1.9% | $39m | 715,452 | -3% |
| InsmedINSM | 1.9% | $39m | 362,150 | +15% |
| PenumbraPEN | 1.8% | $37m | 115,750 | -4% |
| Structure TherapeuticsGPCR | 1.7% | $34m | 640,317 | Held |
| Ultragenyx PharmaceuticalRARE | 1.6% | $32m | 967,855 | -21% |
| iRhythm HoldingsIRTC | 1.6% | $32m | 269,650 | +3% |
| Intuitive SurgicalISRG | 1.5% | $30m | 76,460 | -7% |
| agilon healthAGL | 1.4% | $28m | 262,600 | Held |
| UnitedHealth GroupUNH | 1.3% | $26m | 63,750 | +20% |
| Celldex TherapeuticsCLDX | 1.3% | $26m | 699,146 | +8% |
| ErascaERAS | 1.3% | $26m | 1,402,150 | +27% |
| Neurocrine BiosciencesNBIX | 1.2% | $24m | 144,750 | -4% |
| Enliven TherapeuticsELVN | 1.2% | $24m | 464,625 | -44% |
| Tenet HealthcareTHC | 1.1% | $23m | 125,000 | Held |
| DexcomDXCM | 1.1% | $23m | 343,000 | -4% |
| Aclaris TherapeuticsACRS | 1.1% | $23m | 4,330,532 | -3% |
| MiniMed GroupMMED | 1.1% | $23m | 1,520,000 | +44% |
| Boston ScientificBSX | 1.1% | $23m | 528,500 | +3% |
| PharvarisPHVS | 1.1% | $22m | 648,333 | Held |
| Avalyn PharmaAVLN | 1.1% | $22m | 662,918 | New |
| Hemab Therapeutics HoldingsCOAG | 1.0% | $21m | 575,432 | New |
| Dyne TherapeuticsDYN | 1.0% | $21m | 942,154 | -3% |
| Alnylam PharmaceuticalsALNY | 1.0% | $20m | 66,750 | -10% |
| Cogent BiosciencesCOGT | 1.0% | $20m | 515,917 | -17% |
| Agios PharmaceuticalsAGIO | 1.0% | $20m | 532,563 | -33% |
| NewAmsterdam PharmaNAMS | 1.0% | $20m | 582,744 | Held |
| Vera TherapeuticsVERA | 0.9% | $18m | 427,584 | -15% |
| Tarsus PharmaceuticalsTARS | 0.9% | $17m | 277,087 | +23% |
| HeartflowHTFL | 0.8% | $17m | 573,500 | Held |
| MBX BiosciencesMBX | 0.8% | $16m | 298,218 | +4% |
| CytokineticsCYTK | 0.8% | $16m | 187,980 | +314% |
| Bicara TherapeuticsBCAX | 0.8% | $16m | 535,286 | +9% |
| Parabilis MedicinesPBLS | 0.8% | $16m | 578,028 | New |
| ZAI LABZLAB | 0.8% | $15m | 814,707 | Held |
| DanaherDHR | 0.7% | $15m | 76,300 | +24% |
| Tango TherapeuticsTNGX | 0.7% | $14m | 456,551 | +18% |
| Evolent HealthEVH | 0.7% | $14m | 2,500,000 | -7% |
| PTC TherapeuticsPTCT | 0.6% | $13m | 162,298 | Held |
| Mineralys TherapeuticsMLYS | 0.6% | $13m | 484,951 | +10% |
| Zenas BioPharmaZBIO | 0.6% | $13m | 502,077 | Held |
| ArdelyxARDX | 0.6% | $11m | 2,241,769 | -3% |
| Inspire Medical SystemsINSP | 0.5% | $11m | 244,000 | +85% |
| BridgeBio PharmaBBIO | 0.5% | $11m | 144,750 | +13% |
| Alkermes plc.ALKS | 0.5% | $10m | 199,811 | +9% |
| Summit TherapeuticsSMMT | 0.5% | $10m | 715,000 | Held |
| AzentaAZTA | 0.5% | $10m | 403,000 | -29% |
| Indivior PharmaceuticalsINDV | 0.5% | $10m | 245,500 | +23% |
| StrykerSYK | 0.4% | $9m | 29,000 | +96% |
| Amylyx PharmaceuticalsAMLX | 0.4% | $9m | 499,764 | Held |
| Caris Life SciencesCAI | 0.4% | $9m | 487,500 | -13% |
| Omada HealthOMDA | 0.4% | $8m | 373,000 | -31% |
| Compass TherapeuticsCMPX | 0.4% | $8m | 3,524,929 | +7% |
| ImmunomeIMNM | 0.4% | $7m | 347,666 | Held |
| Edap TMS S AFOCL | 0.4% | $7m | 1,386,000 | Held |
| PhreesiaPHR | 0.4% | $7m | 696,900 | +16% |
| OmerosOMER | 0.3% | $7m | 718,499 | New |
| Definium TherapeuticsDFTX | 0.3% | $7m | 143,187 | New |
| Corcept TherapeuticsCORT | 0.3% | $6m | 72,000 | +43% |
| Janux TherapeuticsJANX | 0.3% | $6m | 367,009 | Held |
| Mobia MedicalMOBI | 0.3% | $6m | 418,200 | New |
| Arcus BiosciencesRCUS | 0.3% | $6m | 180,000 | Held |
| Thermo Fisher ScientificTMO | 0.2% | $5m | 10,000 | Held |
| Trevi TherapeuticsTRVI | 0.2% | $5m | 260,000 | New |
| Sionna TherapeuticsSION | 0.2% | $4m | 99,429 | Held |
| CVS HealthCVS | 0.2% | $4m | 40,000 | Held |
| EyePointEYPT | 0.2% | $4m | 268,519 | +4% |
| Ocular TherapeutixOCUL | 0.2% | $4m | 383,716 | Held |
| Spyre TherapeuticsSYRE | 0.2% | $4m | 42,254 | New |
| TalpheraTLPH | 0.2% | $4m | 3,589,186 | Held |
| Roivant SciencesROIV | 0.2% | $4m | 101,000 | +4% |
| VaxcytePCVX | 0.2% | $4m | 60,250 | Held |
| NeurogeneNGNE | 0.2% | $3m | 106,750 | +2% |
| Century TherapeuticsIPSC | 0.2% | $3m | 1,304,347 | Held |
| Alphatec HoldingsATEC | 0.2% | $3m | 360,000 | +3% |
| Novo Nordisk A SNVO | 0.1% | $3m | 63,500 | -29% |
| Olema PharmaceuticalsOLMA | 0.1% | $3m | 235,178 | +38% |
| Nervgen PharmaNGEN | 0.1% | $2m | 1,208,231 | New |
| MedtronicMDT | 0.1% | $2m | 30,900 | New |
| Teva Pharmaceutical IndustriesTEVA | <0.1% | $2m | 59,000 | +30% |
| Dianthus TherapeuticsDNTH | <0.1% | $2m | 20,326 | -24% |
| Sagimet BiosciencesSGMT | <0.1% | $2m | 250,000 | New |
| Capricor TherapeuticsCAPR | <0.1% | $2m | 74,448 | New |
| LENZ TherapeuticsLENZ | <0.1% | $1m | 257,460 | Held |
| AltimmuneALT | <0.1% | $1m | 471,465 | New |
| Kailera TherapeuticsKLRA | <0.1% | $1m | 65,000 | New |
| Surgery PartnersSGRY | <0.1% | $1m | 84,000 | -60% |
| Axsome TherapeuticsAXSM | <0.1% | $1m | 5,500 | New |
| Oruka TherapeuticsORKA | <0.1% | $1m | 12,051 | +192% |
| Viking TherapeuticsVKTX | <0.1% | $994,755 | 25,500 | -73% |
| Legend BiotechLEGN | <0.1% | $967,480 | 33,500 | -17% |
Showing the largest 100 of 104.
Over time and by industry
Value over time
Jun '25
Dec '25
Jun '26
Value is up 28.1% since 30 June 2025.
Where the money is
Health care93.3%
Industrials1.2%
Technology0.4%
Other5.2%
From the fund's 13F filings. They list US stocks and options only, 45 days after each quarter, and leave out cash, bonds, shorts and foreign shares.