Rock Springs Capital Management LP
In its 13F for Q4 2025 (holdings as of December 31, 2025, filed February 17, 2026), Rock Springs Capital Management LP reported 96 stock positions worth $1.9 billion. Its top holding was Eli Lilly (LLY) at 5.8% of the portfolio, followed by Revolution Medicines (RVMD, 5.5%) and Argenx SE - ADR (ARGX, 4.5%). Compared with Q3 2025, it opened 18 new positions, sold out of 12, added to 32 and reduced 27. The biggest buy was Travere Therapeutics (TVTX, shares +2%) and the biggest sale an exit from Merus (MRUS).
- Most Recent 13F
- Q2 2026
- Location
- Baltimore, MD
- CIK
- 0001595725
- Portfolio Value
- $1.9B (Q4 2025)
- SEC Filing
- 0001172661-26-000917 ↗ filed Feb 17, 2026
Holdings Value
Holdings 96 stocks · $1.9B
| LLY Eli Lilly & Co. | 5.83% | 105,400 | $113.3M | No change |
| RVMD Revolution Medicines Inc. | 5.48% | 1,335,270 | $106.4M | No change |
| ARGX Argenx SE - ADR | 4.47% | 103,250 | $86.8M | Reduce -27.7% |
| TVTX Travere Therapeutics Inc. | 4.35% | 2,210,322 | $84.5M | Add +2.1% |
| MDGL Madrigal Pharmaceuticals Inc. | 4.19% | 139,618 | $81.3M | Add +1.4% |
| RYTM Rhythm Pharmaceuticals Inc. | 3.83% | 695,010 | $74.4M | Reduce -3.1% |
| EXAS Exact Sciences Corp. | 3.15% | 601,800 | $61.1M | Add +1.4% |
| MIRM Mirum Pharmaceuticals Inc. | 3.10% | 762,294 | $60.2M | Add +0.1% |
| INSM Insmed Inc. | 2.86% | 319,250 | $55.6M | Reduce -17.1% |
| GPCR Structure Therapeutics Inc. | 2.68% | 748,236 | $52.0M | Reduce -21.3% |
| ISRG Intuitive Surgical Inc. | 2.39% | 82,000 | $46.4M | No change |
| CDTX Cidara Therapeutics Inc. | 2.33% | 204,878 | $45.3M | Reduce -17.9% |
| ASND Ascendis Pharma A/S | 2.23% | 203,500 | $43.4M | Reduce -5.1% |
| IRTC Irhythm Holdings Inc. | 2.15% | 235,000 | $41.7M | No change |
| KYMR Kymera Therapeutics Inc. | 1.99% | 496,871 | $38.7M | Add +10.3% |
| BSX Boston Scientific Corp. | 1.96% | 399,050 | $38.0M | Add +10.8% |
| PEN Penumbra Inc. | 1.93% | 120,500 | $37.5M | No change |
| XENE Xenon Pharmaceuticals Inc. | 1.82% | 787,788 | $35.3M | Reduce -7.5% |
| SRRK Scholar Rock Holding Corp. | 1.66% | 733,477 | $32.3M | Reduce -7.6% |
| COGT Cogent Biosciences Inc. | 1.55% | 849,030 | $30.2M | Reduce -15.8% |
| RARE Ultragenyx Pharmaceutical Inc. | 1.50% | 1,267,241 | $29.1M | Add +1.7% |
| VERA Vera Therapeutics Inc. | 1.48% | 568,579 | $28.8M | Reduce -7.9% |
| ALNY Alnylam Pharmaceuticals Inc. | 1.46% | 71,250 | $28.3M | Reduce -4.0% |
| FOLD Amicus Therapeutics Inc. | 1.41% | 1,929,931 | $27.5M | Reduce -0.9% |
| XBI SS SPDR S&P Biotech ETF | 1.39% | 222,000 | $27.1M | Add +46.3% |
| THC Tenet Healthcare Corp. | 1.28% | 125,000 | $24.8M | No change |
| DXCM Dexcom Inc. | 1.19% | 347,300 | $23.1M | Add +9.6% |
| AGIO Agios Pharmaceuticals Inc. | 1.12% | 799,163 | $21.8M | Reduce -16.6% |
| TARS Tarsus Pharmaceuticals Inc. | 1.10% | 260,344 | $21.3M | Reduce -9.7% |
| CMPX Compass Therapeutics Inc. | 1.09% | 3,927,202 | $21.1M | Reduce -12.2% |
| NAMS Newamsterdam Pharma Co. NV | 1.01% | 557,194 | $19.5M | Reduce -6.5% |
| AZTA Azenta Inc. | 0.97% | 569,100 | $18.9M | Add +5.3% |
| CLDX Celldex Therapeutics Inc. | 0.97% | 692,538 | $18.8M | Reduce -4.0% |
| CAI Caris Life Sciences Inc. | 0.95% | 687,500 | $18.5M | Reduce -13.4% |
| ZBIO Zenas Biopharma Inc. | 0.94% | 502,077 | $18.2M | Reduce -13.5% |
| DYN Dyne Therapeutics Inc. | 0.92% | 912,955 | $17.9M | Add +10.8% |
| NBIX Neurocrine Biosciences Inc. | 0.92% | 125,500 | $17.8M | Add +39.8% |
| PHVS Pharvaris NV | 0.89% | 623,402 | $17.3M | No change |
| MLYS Mineralys Therapeutics Inc. | 0.80% | 427,596 | $15.5M | Add +4.7% |
| PHR Phreesia Inc. | 0.76% | 876,600 | $14.8M | Add +17.0% |
| ZLAB Zai Lab Ltd.-ADR | 0.74% | 811,546 | $14.3M | Add +2.6% |
| DHR Danaher Corp. | 0.72% | 61,500 | $14.1M | No change |
| UNH Unitedhealth Group Inc. | 0.69% | 40,800 | $13.5M | New |
| ARDX Ardelyx Inc. | 0.69% | 2,299,473 | $13.4M | Add +0.6% |
| ACRS Aclaris Therapeutics Inc. | 0.69% | 4,453,741 | $13.4M | Reduce -3.4% |
| SMMT Summit Therapeutics Inc. | 0.64% | 710,000 | $12.4M | No change |
| ELVN Enliven Therapeutics Inc. | 0.63% | 798,405 | $12.3M | Add +16.4% |
| INSP Inspire Medical Systems Inc. | 0.62% | 131,000 | $12.1M | Add +18.6% |
| OMDA Omada Health Inc. | 0.60% | 740,000 | $11.7M | Reduce -19.6% |
| SLNO Soleno Therapeutics Inc. | 0.59% | 247,053 | $11.4M | Add +59.9% |
| ACLX Arcellx Inc. | 0.57% | 169,859 | $11.1M | Reduce -5.1% |
| EVH Evolent Health Inc. Class A | 0.55% | 2,675,000 | $10.7M | Reduce -9.3% |
| GOSS Gossamer Bio Inc. | 0.52% | 3,266,960 | $10.1M | No change |
| MBX MBX Biosciences Inc. | 0.46% | 282,624 | $8.9M | No change |
| CNTA Centessa Pharmaceuticals Ltd. | 0.42% | 324,015 | $8.1M | Add +368.0% |
| HTFL Heartflow Inc. | 0.42% | 277,700 | $8.1M | Add +11.1% |
| BBIO Bridgebio Pharma Inc. | 0.41% | 103,500 | $7.9M | Add +21.8% |
| REGN Regeneron Pharmaceuticals | 0.40% | 10,100 | $7.8M | Reduce -10.6% |
| IMNM Immunome Inc. | 0.38% | 347,666 | $7.5M | New |
| RAPT Rapt Therapeutics Inc. | 0.37% | 213,731 | $7.2M | New |
| BCAX Bicara Therapeutics Inc. | 0.37% | 429,095 | $7.2M | Add +15.8% |
| EW Edwards Lifesciences Corp. | 0.36% | 82,500 | $7.0M | Reduce -6.3% |
| ATEC Alphatec Holdings Inc. | 0.33% | 302,500 | $6.4M | No change |
| AMLX Amylyx Pharmaceuticals Inc. | 0.31% | 499,764 | $6.0M | No change |
| TMO Thermo Fisher Scientific Inc. | 0.30% | 10,000 | $5.8M | No change |
| JANX Janux Therapeutics Inc. | 0.25% | 358,798 | $5.0M | Add +70.6% |
| SGRY Surgery Partners Inc. | 0.25% | 310,000 | $4.8M | New |
| EYPT Eyepoint Inc. | 0.24% | 258,739 | $4.7M | Add +717.4% |
| PTCT PTC Therapeutics Inc. | 0.24% | 61,879 | $4.7M | New |
| AGL Agilon Health Inc. | 0.23% | 6,500,000 | $4.5M | Reduce -6.7% |
| MRSN Mersana Therapeutics Inc. | 0.23% | 152,586 | $4.4M | No change |
| TERN Terns Pharmaceuticals Inc. | 0.23% | 108,481 | $4.4M | New |
| RCUS Arcus Biosciences Inc. | 0.22% | 180,000 | $4.3M | New |
| FOCL Edap TMS SA -ADR | 0.22% | 1,286,500 | $4.2M | Add +1.3% |
| OCUL Ocular Therapeutix Inc. | 0.22% | 345,820 | $4.2M | Add +15.3% |
| LENZ Lenz Therapeutics Inc. | 0.21% | 257,460 | $4.1M | Add +9.0% |
| TLPH Talphera Inc. | 0.21% | 3,589,186 | $4.1M | No change |
| SION Sionna Therapeutics Inc. | 0.21% | 99,429 | $4.1M | No change |
| TBPH Theravance Biopharma Inc. | 0.20% | 208,771 | $3.9M | New |
| ALKS Alkermes PLC | 0.20% | 139,228 | $3.9M | Add +30.7% |
| APLS Apellis Pharmaceuticals Inc. | 0.19% | 150,500 | $3.8M | Add +63.6% |
| INDV Indivior Ltd. | 0.19% | 105,100 | $3.8M | New |
| ERAS Erasca Inc. | 0.18% | 951,710 | $3.5M | New |
| TNGX Tango Therapeutics Inc. | 0.18% | 386,915 | $3.4M | New |
| OLMA Olema Pharmaceuticals Inc. | 0.13% | 98,240 | $2.5M | New |
| CYTK Cytokinetics Inc. | 0.12% | 35,853 | $2.3M | New |
| PCVX Vaxcyte Inc. | 0.11% | 47,000 | $2.2M | Add +323.4% |
| NGNE Neurogene Inc. | 0.11% | 104,339 | $2.1M | No change |
| JSPR Jasper Therapeutics Inc. | 0.10% | 1,100,726 | $2.0M | No change |
| ROIV Roivant Sciences Ltd. | 0.10% | 88,750 | $1.9M | New |
| CORT Corcept Therapeutics Inc. | 0.09% | 50,250 | $1.7M | New |
| ACHC Acadia Healthcare Co. Inc. | 0.09% | 120,000 | $1.7M | Reduce -29.4% |
| TEVA Teva Pharmaceutical-SP ADR | 0.07% | 45,500 | $1.4M | New |
| MLTX Moonlake Immunotherapeutics | 0.04% | 61,700 | $813K | Add +118.8% |
| LEGN Legend Biotech Corp.-ADR | 0.04% | 33,800 | $735K | New |
| JAZZ Jazz Pharmaceuticals PLC | 0.02% | 1,750 | $298K | New |
Options reported separately and not counted above: NAMS calls ($1.1M).
Other holdings (2): bonds, preferreds, convertibles and warrants · $6.6M (not counted above)
| Security | Class | Shares / Principal | Value | Change |
|---|---|---|---|---|
| GOSSAMER BIO INC (GOSS 5 06/01/27) | NOTE 5.000% 6/0 · principal | 9,573,000 | $6.6M | No change |
| NUVB.WS Nuvation Bio Inc. -CW27 | *W EXP 02/10/202 | 134,028 | $44K | No change |
Total filed on the 13F, all lines: $1.9B.
Portfolio Sells Q3 2025 → Q4 2025
| MRUS Merus NV | Sold out | 0.00% | −3.30 |
| AKRO Akero Therapeutics Inc. | Sold out | 0.00% | −1.75 |
| ARGX Argenx SE - ADR | Reduce -27.7% | 4.47% | −1.71 |
| AGIO Agios Pharmaceuticals Inc. | Reduce -16.6% | 1.12% | −1.14 |
| EVH Evolent Health Inc. Class A | Reduce -9.3% | 0.55% | −0.91 |
| OMDA Omada Health Inc. | Reduce -19.6% | 0.60% | −0.59 |
| MREO Mereo Biopharma Group PL-ADR | Sold out | 0.00% | −0.55 |
| ALNY Alnylam Pharmaceuticals Inc. | Reduce -4.0% | 1.46% | −0.53 |
| CAI Caris Life Sciences Inc. | Reduce -13.4% | 0.95% | −0.45 |
| RYTM Rhythm Pharmaceuticals Inc. | Reduce -3.1% | 3.83% | −0.42 |
| INSM Insmed Inc. | Reduce -17.1% | 2.86% | −0.39 |
| ACLX Arcellx Inc. | Reduce -5.1% | 0.57% | −0.29 |
| ASND Ascendis Pharma A/S | Reduce -5.1% | 2.23% | −0.27 |
| AGL Agilon Health Inc. | Reduce -6.7% | 0.23% | −0.19 |
| XENE Xenon Pharmaceuticals Inc. | Reduce -7.5% | 1.82% | −0.19 |
| ACHC Acadia Healthcare Co. Inc. | Reduce -29.4% | 0.09% | −0.16 |
| WST West Pharmaceutical Services | Sold out | 0.00% | −0.15 |
| CLDX Celldex Therapeutics Inc. | Reduce -4.0% | 0.97% | −0.13 |
| KRRO Korro Bio Inc. | Sold out | 0.00% | −0.10 |
| CATX Perspective Therapeutics Inc. | Sold out | 0.00% | −0.09 |
| APLT Applied Therapeutics Inc. | Sold out | 0.00% | −0.07 |
| SRRK Scholar Rock Holding Corp. | Reduce -7.6% | 1.66% | −0.07 |
| IMVT Immunovant Inc. | Sold out | 0.00% | −0.07 |
| EW Edwards Lifesciences Corp. | Reduce -6.3% | 0.36% | −0.04 |
| CRL Charles River Laboratories | Sold out | 0.00% | −0.02 |
| NVAX Novavax Inc. | Sold out | 0.00% | −0.02 |
| PRTA Prothena Corp. PLC | Sold out | 0.00% | −0.01 |
| CGEN Compugen Ltd. | Sold out | 0.00% | −0.00 |
| NAMS Newamsterdam Pharma Co. NV | Reduce -6.5% | 1.01% | +0.01 |
| REGN Regeneron Pharmaceuticals | Reduce -10.6% | 0.40% | +0.03 |
| TARS Tarsus Pharmaceuticals Inc. | Reduce -9.7% | 1.10% | +0.09 |
| CMPX Compass Therapeutics Inc. | Reduce -12.2% | 1.09% | +0.17 |
| ACRS Aclaris Therapeutics Inc. | Reduce -3.4% | 0.69% | +0.18 |
| ZBIO Zenas Biopharma Inc. | Reduce -13.5% | 0.94% | +0.18 |
| VERA Vera Therapeutics Inc. | Reduce -7.9% | 1.48% | +0.43 |
| FOLD Amicus Therapeutics Inc. | Reduce -0.9% | 1.41% | +0.51 |
| COGT Cogent Biosciences Inc. | Reduce -15.8% | 1.55% | +0.70 |
| CDTX Cidara Therapeutics Inc. | Reduce -17.9% | 2.33% | +0.93 |
| GPCR Structure Therapeutics Inc. | Reduce -21.3% | 2.68% | +1.12 |
Portfolio Buys Q3 2025 → Q4 2025
| TVTX Travere Therapeutics Inc. | Add +2.1% | 4.35% | +1.31 |
| EXAS Exact Sciences Corp. | Add +1.4% | 3.15% | +1.24 |
| UNH Unitedhealth Group Inc. | New | 0.69% | +0.69 |
| XBI SS SPDR S&P Biotech ETF | Add +46.3% | 1.39% | +0.50 |
| KYMR Kymera Therapeutics Inc. | Add +10.3% | 1.99% | +0.49 |
| MDGL Madrigal Pharmaceuticals Inc. | Add +1.4% | 4.19% | +0.48 |
| IMNM Immunome Inc. | New | 0.38% | +0.38 |
| RAPT Rapt Therapeutics Inc. | New | 0.37% | +0.37 |
| CNTA Centessa Pharmaceuticals Ltd. | Add +368.0% | 0.42% | +0.32 |
| DYN Dyne Therapeutics Inc. | Add +10.8% | 0.92% | +0.31 |
| SGRY Surgery Partners Inc. | New | 0.25% | +0.25 |
| PTCT PTC Therapeutics Inc. | New | 0.24% | +0.24 |
| TERN Terns Pharmaceuticals Inc. | New | 0.23% | +0.23 |
| RCUS Arcus Biosciences Inc. | New | 0.22% | +0.22 |
| EYPT Eyepoint Inc. | Add +717.4% | 0.24% | +0.22 |
| TBPH Theravance Biopharma Inc. | New | 0.20% | +0.20 |
| INDV Indivior Ltd. | New | 0.19% | +0.19 |
| ERAS Erasca Inc. | New | 0.18% | +0.18 |
| NBIX Neurocrine Biosciences Inc. | Add +39.8% | 0.92% | +0.18 |
| TNGX Tango Therapeutics Inc. | New | 0.18% | +0.18 |
| BBIO Bridgebio Pharma Inc. | Add +21.8% | 0.41% | +0.15 |
| INSP Inspire Medical Systems Inc. | Add +18.6% | 0.62% | +0.14 |
| OLMA Olema Pharmaceuticals Inc. | New | 0.13% | +0.13 |
| CYTK Cytokinetics Inc. | New | 0.12% | +0.12 |
| ROIV Roivant Sciences Ltd. | New | 0.10% | +0.10 |
| CORT Corcept Therapeutics Inc. | New | 0.09% | +0.09 |
| PCVX Vaxcyte Inc. | Add +323.4% | 0.11% | +0.09 |
| TEVA Teva Pharmaceutical-SP ADR | New | 0.07% | +0.07 |
| APLS Apellis Pharmaceuticals Inc. | Add +63.6% | 0.19% | +0.07 |
| AZTA Azenta Inc. | Add +5.3% | 0.97% | +0.06 |
| FOCL Edap TMS SA -ADR | Add +1.3% | 0.22% | +0.05 |
| LEGN Legend Biotech Corp.-ADR | New | 0.04% | +0.04 |
| MLTX Moonlake Immunotherapeutics | Add +118.8% | 0.04% | +0.03 |
| BCAX Bicara Therapeutics Inc. | Add +15.8% | 0.37% | +0.03 |
| JAZZ Jazz Pharmaceuticals PLC | New | 0.02% | +0.02 |
| ALKS Alkermes PLC | Add +30.7% | 0.20% | +0.01 |
| OCUL Ocular Therapeutix Inc. | Add +15.3% | 0.22% | +0.01 |
| SLNO Soleno Therapeutics Inc. | Add +59.9% | 0.59% | −0.02 |
| JANX Janux Therapeutics Inc. | Add +70.6% | 0.25% | −0.05 |
| ARDX Ardelyx Inc. | Add +0.6% | 0.69% | −0.05 |
| DXCM Dexcom Inc. | Add +9.6% | 1.19% | −0.06 |
| HTFL Heartflow Inc. | Add +11.1% | 0.42% | −0.08 |
| BSX Boston Scientific Corp. | Add +10.8% | 1.96% | −0.11 |
| MLYS Mineralys Therapeutics Inc. | Add +4.7% | 0.80% | −0.11 |
| MIRM Mirum Pharmaceuticals Inc. | Add +0.1% | 3.10% | −0.17 |
| ELVN Enliven Therapeutics Inc. | Add +16.4% | 0.63% | −0.19 |
| PHR Phreesia Inc. | Add +17.0% | 0.76% | −0.27 |
| LENZ Lenz Therapeutics Inc. | Add +9.0% | 0.21% | −0.43 |
| RARE Ultragenyx Pharmaceutical Inc. | Add +1.7% | 1.50% | −0.70 |
| ZLAB Zai Lab Ltd.-ADR | Add +2.6% | 0.74% | −0.84 |
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 104 | $2.0B | RVMD, TVTX, LLY, MDGL, MIRM |
| Q1 2026 | 100 | $1.7B | RVMD, LLY, MDGL, MIRM, ARGX |
| Q4 2025 | 96 | $1.9B | LLY, RVMD, ARGX, TVTX, MDGL |
| Q3 2025 | 90 | $1.7B | ARGX, LLY, RYTM, MDGL, RVMD |
| Q2 2025 | 91 | $1.6B | ARGX, LLY, MRUS, RYTM, INSM |
| Q1 2025 | 94 | $1.7B | ARGX, LLY, BPMC, MDGL, UNH |
| Q4 2024 | 104 | $2.6B | ARGX, ISRG, LLY, NBIX, BPMC |
| Q3 2024 | 106 | $3.1B | UNH, ISRG, ARGX, LLY, RARE |
| Q2 2024 | 106 | $3.3B | BPMC, UNH, ISRG, NBIX, LLY |
| Q1 2024 | 108 | $3.9B | BPMC, IMCR, NBIX, EVH, ISRG |