Rock Springs Capital Management LP
In its 13F for Q4 2024 (holdings as of December 31, 2024, filed February 14, 2025), Rock Springs Capital Management LP reported 104 stock positions worth $2.6 billion. Its top holding was Argenx SE - ADR (ARGX) at 5.4% of the portfolio, followed by Intuitive Surgical (ISRG, 4.3%) and Eli Lilly (LLY, 4.3%). Compared with Q3 2024, it opened 10 new positions, sold out of 12, added to 38 and reduced 30. The biggest buy was Blueprint Medicines (BPMC, shares +43%) and the biggest sale Unitedhealth (UNH, shares −40%).
- Most Recent 13F
- Q2 2026
- Location
- Baltimore, MD
- CIK
- 0001595725
- Portfolio Value
- $2.6B (Q4 2024)
- SEC Filing
- 0001172661-25-000867 ↗ filed Feb 14, 2025
Holdings Value
Holdings 104 stocks · $2.6B
| ARGX Argenx SE - ADR | 5.39% | 229,600 | $141.2M | Reduce -1.7% |
| ISRG Intuitive Surgical Inc. | 4.30% | 216,000 | $112.7M | Reduce -20.0% |
| LLY Eli Lilly & Co. | 4.26% | 144,500 | $111.6M | Add +1.8% |
| NBIX Neurocrine Biosciences Inc. | 3.75% | 720,500 | $98.3M | Reduce -23.3% |
| BPMC Blueprint Medicines Corp. | 3.65% | 1,096,899 | $95.7M | Add +42.7% |
| UNH Unitedhealth Group Inc. | 3.40% | 176,000 | $89.0M | Reduce -40.2% |
| TVTX Travere Therapeutics Inc. | 3.31% | 4,973,649 | $86.6M | Add +6.2% |
| MDGL Madrigal Pharmaceuticals Inc. | 3.12% | 265,212 | $81.8M | Add +0.8% |
| RARE Ultragenyx Pharmaceutical Inc. | 2.79% | 1,739,813 | $73.2M | Reduce -12.1% |
| RYTM Rhythm Pharmaceuticals Inc. | 2.48% | 1,162,718 | $65.1M | Reduce -5.3% |
| MIRM Mirum Pharmaceuticals Inc. | 2.32% | 1,471,564 | $60.8M | Reduce -6.9% |
| ALNY Alnylam Pharmaceuticals Inc. | 2.30% | 256,200 | $60.3M | Add +2.5% |
| PEN Penumbra Inc. | 2.17% | 240,000 | $57.0M | Reduce -9.4% |
| WST West Pharmaceutical Services | 2.11% | 168,750 | $55.3M | Add +0.6% |
| RVMD Revolution Medicines Inc. | 2.02% | 1,213,257 | $53.1M | Add +20.1% |
| PHR Phreesia Inc. | 1.96% | 2,040,000 | $51.3M | Reduce -10.6% |
| XENE Xenon Pharmaceuticals Inc. | 1.87% | 1,251,859 | $49.1M | Reduce -4.9% |
| FRPT Freshpet Inc. | 1.85% | 327,500 | $48.5M | Reduce -26.6% |
| ASND Ascendis Pharma A/S | 1.60% | 305,000 | $42.0M | Reduce -6.2% |
| KYMR Kymera Therapeutics Inc. | 1.59% | 1,034,137 | $41.6M | Reduce -1.4% |
| BSX Boston Scientific Corp. | 1.57% | 460,000 | $41.1M | No change |
| EW Edwards Lifesciences Corp. | 1.54% | 545,000 | $40.3M | Reduce -5.5% |
| INSM Insmed Inc. | 1.45% | 550,000 | $38.0M | Reduce -19.5% |
| MRUS Merus NV | 1.43% | 892,549 | $37.5M | No change |
| SRPT Sarepta Therapeutics Inc. | 1.43% | 307,500 | $37.4M | No change |
| IRTC Irhythm Holdings Inc. | 1.37% | 397,500 | $35.8M | No change |
| ZLAB Zai Lab Ltd.-ADR | 1.30% | 1,305,337 | $34.2M | Reduce -0.8% |
| NUVL Nuvalent Inc. Class A | 1.28% | 429,994 | $33.7M | No change |
| MREO Mereo Biopharma Group PL-ADR | 1.28% | 9,599,170 | $33.6M | Add +0.7% |
| SRRK Scholar Rock Holding Corp. | 1.18% | 716,782 | $31.0M | New |
| CLDX Celldex Therapeutics Inc. | 1.18% | 1,222,182 | $30.9M | Add +10.7% |
| PODD Insulet Corp. | 1.14% | 114,250 | $29.8M | Reduce -14.7% |
| GPCR Structure Therapeutics Inc. | 1.12% | 1,080,963 | $29.3M | Add +1.6% |
| DXCM Dexcom Inc. | 1.05% | 353,000 | $27.5M | Reduce -32.6% |
| AKRO Akero Therapeutics Inc. | 1.00% | 946,499 | $26.3M | Add +1.4% |
| EXAS Exact Sciences Corp. | 0.96% | 450,000 | $25.3M | Reduce -60.8% |
| FOLD Amicus Therapeutics Inc. | 0.93% | 2,599,425 | $24.5M | Add +107.9% |
| INSP Inspire Medical Systems Inc. | 0.92% | 130,000 | $24.1M | No change |
| AZTA Azenta Inc. | 0.91% | 475,000 | $23.8M | Reduce -10.8% |
| EVH Evolent Health Inc. Class A | 0.88% | 2,060,000 | $23.2M | Reduce -0.5% |
| ACHC Acadia Healthcare Co. Inc. | 0.88% | 583,500 | $23.1M | Reduce -28.4% |
| IMVT Immunovant Inc. | 0.86% | 909,103 | $22.5M | Reduce -25.6% |
| WRBY Warby Parker Inc. Class A | 0.85% | 920,000 | $22.3M | Reduce -36.1% |
| VERA Vera Therapeutics Inc. | 0.79% | 487,863 | $20.6M | Add +27.2% |
| BCRX Biocryst Pharmaceuticals Inc. | 0.77% | 2,677,996 | $20.1M | Reduce -26.1% |
| NAMS Newamsterdam Pharma Co. NV | 0.75% | 767,522 | $19.7M | Add +117.2% |
| SMMT Summit Therapeutics Inc. | 0.72% | 1,054,000 | $18.8M | Add +1.4% |
| LFST Lifestance Health Group Inc. | 0.72% | 2,550,000 | $18.8M | Reduce -17.8% |
| LEGN Legend Biotech Corp.-ADR | 0.64% | 512,132 | $16.7M | Add +0.6% |
| THC Tenet Healthcare Corp. | 0.62% | 129,200 | $16.3M | New |
| AGIO Agios Pharmaceuticals Inc. | 0.59% | 471,086 | $15.5M | Reduce -32.6% |
| ACRS Aclaris Therapeutics Inc. | 0.59% | 6,204,309 | $15.4M | Add +125.3% |
| CRNX Crinetics Pharmaceuticals Inc. | 0.57% | 294,100 | $15.0M | Add +1.6% |
| PHVS Pharvaris NV | 0.57% | 775,131 | $14.9M | Add +2.4% |
| AGL Agilon Health Inc. | 0.54% | 7,463,300 | $14.2M | Reduce -18.0% |
| OSCR Oscar Health Inc. Class A | 0.54% | 1,050,000 | $14.1M | Add +3.8% |
| SWTX Springworks Therapeutics Inc. | 0.45% | 328,911 | $11.9M | Add +64.6% |
| DYN Dyne Therapeutics Inc. | 0.43% | 474,528 | $11.2M | Add +2.9% |
| JANX Janux Therapeutics Inc. | 0.42% | 204,466 | $10.9M | New |
| INZY Inozyme Pharma Inc. | 0.41% | 3,861,983 | $10.7M | Add +1.6% |
| NMRA Neumora Therapeutics Inc. | 0.39% | 955,106 | $10.1M | Add +15.3% |
| JSPR Jasper Therapeutics Inc. | 0.38% | 463,088 | $9.9M | Add +0.9% |
| ELVN Enliven Therapeutics Inc. | 0.37% | 428,571 | $9.6M | No change |
| XNCR Xencor Inc. | 0.35% | 401,013 | $9.2M | No change |
| CGEM Cullinan Therapeutics Inc. | 0.34% | 742,114 | $9.0M | Add +0.7% |
| PRTA Prothena Corp. PLC | 0.34% | 644,601 | $8.9M | Add +3.1% |
| CMPX Compass Therapeutics Inc. | 0.32% | 5,779,575 | $8.4M | Add +2.7% |
| BCAX Bicara Therapeutics Inc. | 0.30% | 445,975 | $7.8M | No change |
| ARDX Ardelyx Inc. | 0.28% | 1,463,629 | $7.4M | New |
| ZBIO Zenas Biopharma Inc. | 0.27% | 878,667 | $7.2M | No change |
| BEAM Beam Therapeutics Inc. | 0.24% | 252,223 | $6.3M | Add +0.9% |
| TARS Tarsus Pharmaceuticals Inc. | 0.23% | 110,889 | $6.1M | New |
| NVRO Nevro LLC filed as NEVRO CORP | 0.23% | 1,648,100 | $6.1M | Add +19.3% |
| SLNO Soleno Therapeutics Inc. | 0.21% | 124,095 | $5.6M | New |
| PLRX Pliant Therapeutics Inc. | 0.20% | 404,796 | $5.3M | Add +5.1% |
| LUNG Pulmonx Corp. | 0.20% | 772,151 | $5.2M | Add +11.7% |
| NVAX Novavax Inc. | 0.20% | 650,000 | $5.2M | No change |
| MERSANA THERAPEUTICS INC | 0.19% | 3,431,684 | $4.9M | Add +12.6% |
| BHVN Biohaven Ltd. | 0.18% | 129,858 | $4.9M | Add +1.8% |
| ETNB 89BIO Inc. | 0.16% | 552,741 | $4.3M | New |
| CYPH Cypherpunk Technologies Inc. filed as LEAP THERAPEUTICS INC | 0.14% | 1,266,546 | $3.6M | No change |
| SGMT Sagimet Biosciences Inc. Class A | 0.14% | 787,808 | $3.5M | No change |
| FOCL Edap TMS SA -ADR | 0.13% | 1,591,800 | $3.5M | Add +1.5% |
| MGNX Macrogenics Inc. | 0.13% | 1,053,647 | $3.4M | No change |
| ABOS Acumen Pharmaceuticals Inc. | 0.12% | 1,838,916 | $3.2M | Reduce -20.1% |
| GOSS Gossamer Bio Inc. | 0.11% | 3,266,960 | $3.0M | No change |
| XLO Xilio Therapeutics Inc. | 0.11% | 3,003,259 | $2.9M | No change |
| APLS Apellis Pharmaceuticals Inc. | 0.10% | 80,000 | $2.6M | No change |
| AUTL Autolus Therapeutics PLC | 0.09% | 1,032,988 | $2.4M | No change |
| NGNE Neurogene Inc. | 0.08% | 95,407 | $2.2M | New |
| ATEC Alphatec Holdings Inc. | 0.07% | 200,000 | $1.8M | New |
| APLT Applied Therapeutics Inc. | 0.06% | 1,917,191 | $1.6M | Add +9.8% |
| CGEN Compugen Ltd. | 0.06% | 989,990 | $1.5M | No change |
| CATX Perspective Therapeutics Inc. | 0.05% | 444,383 | $1.4M | Add +7.2% |
| KRRO Korro Bio Inc. | 0.05% | 35,719 | $1.4M | No change |
| ADAPY Adaptimmune Therapeutics-ADR | 0.05% | 2,483,468 | $1.3M | Add +2.4% |
| ALLK Allakos LLC | 0.05% | 1,100,409 | $1.3M | Reduce -8.3% |
| SPRB Spruce Biosciences Inc. | 0.04% | 2,609,125 | $1.1M | No change |
| LENZ Lenz Therapeutics Inc. | 0.03% | 29,305 | $846K | New |
| VIGL Vigil Neuroscience Inc. | 0.03% | 471,958 | $802K | No change |
| BMEA Biomea Fusion Inc. | 0.03% | 181,147 | $703K | No change |
| KYTX Kyverna Therapeutics Inc. | 0.03% | 178,963 | $669K | No change |
| VINCERX PHARMA INC | 0.01% | 891,719 | $234K | No change |
| TLPH Talphera Inc. | 0.01% | 316,460 | $166K | No change |
Other holdings (3): bonds, preferreds, convertibles and warrants · $5.6M (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 | $5.1M | No change |
| NEVRO CORP (NVRO 2.75 04/01/25) | NOTE 2.750% 4/0 · principal | 500,000 | $489K | No change |
| NUVB.WS Nuvation Bio Inc. -CW27 | *W EXP 02/10/202 | 134,028 | $31K | No change |
Total filed on the 13F, all lines: $2.6B.
Portfolio Sells Q3 2024 → Q4 2024
| UNH Unitedhealth Group Inc. | Reduce -40.2% | 3.40% | −2.21 |
| EXAS Exact Sciences Corp. | Reduce -60.8% | 0.96% | −1.58 |
| HUM Humana Inc. | Sold out | 0.00% | −1.53 |
| EVH Evolent Health Inc. Class A | Reduce -0.5% | 0.88% | −1.02 |
| ALGN Align Technology Inc. | Sold out | 0.00% | −0.95 |
| ACHC Acadia Healthcare Co. Inc. | Reduce -28.4% | 0.88% | −0.80 |
| RARE Ultragenyx Pharmaceutical Inc. | Reduce -12.1% | 2.79% | −0.79 |
| AGL Agilon Health Inc. | Reduce -18.0% | 0.54% | −0.62 |
| NVO Novo-Nordisk A/S-Spons ADR | Sold out | 0.00% | −0.51 |
| JNJ Johnson & Johnson | Sold out | 0.00% | −0.42 |
| AGIO Agios Pharmaceuticals Inc. | Reduce -32.6% | 0.59% | −0.42 |
| CYTK Cytokinetics Inc. | Sold out | 0.00% | −0.35 |
| BMRN Biomarin Pharmaceutical Inc. | Sold out | 0.00% | −0.35 |
| KRYS Krystal Biotech Inc. | Sold out | 0.00% | −0.33 |
| AUPH Aurinia Pharmaceuticals Inc. | Sold out | 0.00% | −0.28 |
| IMVT Immunovant Inc. | Reduce -25.6% | 0.86% | −0.28 |
| DVAX Dynavax Technologies Corp. | Sold out | 0.00% | −0.22 |
| PCRX Pacira Biosciences Inc. | Sold out | 0.00% | −0.20 |
| INSM Insmed Inc. | Reduce -19.5% | 1.45% | −0.18 |
| FRPT Freshpet Inc. | Reduce -26.6% | 1.85% | −0.14 |
| EPIX Essa Pharma Inc. | Sold out | 0.00% | −0.13 |
| BCRX Biocryst Pharmaceuticals Inc. | Reduce -26.1% | 0.77% | −0.13 |
| DXCM Dexcom Inc. | Reduce -32.6% | 1.05% | −0.10 |
| ABOS Acumen Pharmaceuticals Inc. | Reduce -20.1% | 0.12% | −0.07 |
| KYMR Kymera Therapeutics Inc. | Reduce -1.4% | 1.59% | −0.03 |
| ISRG Intuitive Surgical Inc. | Reduce -20.0% | 4.30% | −0.02 |
| ACCD Accolade Inc. | Sold out | 0.00% | −0.02 |
| LFST Lifestance Health Group Inc. | Reduce -17.8% | 0.72% | +0.01 |
| ASND Ascendis Pharma A/S | Reduce -6.2% | 1.60% | +0.02 |
| ALLK Allakos LLC | Reduce -8.3% | 0.05% | +0.03 |
| AZTA Azenta Inc. | Reduce -10.8% | 0.91% | +0.07 |
| WRBY Warby Parker Inc. Class A | Reduce -36.1% | 0.85% | +0.08 |
| PODD Insulet Corp. | Reduce -14.7% | 1.14% | +0.12 |
| XENE Xenon Pharmaceuticals Inc. | Reduce -4.9% | 1.87% | +0.18 |
| NBIX Neurocrine Biosciences Inc. | Reduce -23.3% | 3.75% | +0.23 |
| PHR Phreesia Inc. | Reduce -10.6% | 1.96% | +0.26 |
| ZLAB Zai Lab Ltd.-ADR | Reduce -0.8% | 1.30% | +0.27 |
| EW Edwards Lifesciences Corp. | Reduce -5.5% | 1.54% | +0.30 |
| MIRM Mirum Pharmaceuticals Inc. | Reduce -6.9% | 2.32% | +0.31 |
| RYTM Rhythm Pharmaceuticals Inc. | Reduce -5.3% | 2.48% | +0.39 |
| PEN Penumbra Inc. | Reduce -9.4% | 2.17% | +0.50 |
| ARGX Argenx SE - ADR | Reduce -1.7% | 5.39% | +1.26 |
Portfolio Buys Q3 2024 → Q4 2024
| BPMC Blueprint Medicines Corp. | Add +42.7% | 3.65% | +1.33 |
| MDGL Madrigal Pharmaceuticals Inc. | Add +0.8% | 3.12% | +1.30 |
| SRRK Scholar Rock Holding Corp. | New | 1.18% | +1.18 |
| TVTX Travere Therapeutics Inc. | Add +6.2% | 3.31% | +1.17 |
| THC Tenet Healthcare Corp. | New | 0.62% | +0.62 |
| NAMS Newamsterdam Pharma Co. NV | Add +117.2% | 0.75% | +0.56 |
| RVMD Revolution Medicines Inc. | Add +20.1% | 2.02% | +0.53 |
| FOLD Amicus Therapeutics Inc. | Add +107.9% | 0.93% | +0.50 |
| ACRS Aclaris Therapeutics Inc. | Add +125.3% | 0.59% | +0.48 |
| WST West Pharmaceutical Services | Add +0.6% | 2.11% | +0.47 |
| JANX Janux Therapeutics Inc. | New | 0.42% | +0.42 |
| ARDX Ardelyx Inc. | New | 0.28% | +0.28 |
| SWTX Springworks Therapeutics Inc. | Add +64.6% | 0.45% | +0.24 |
| VERA Vera Therapeutics Inc. | Add +27.2% | 0.79% | +0.23 |
| TARS Tarsus Pharmaceuticals Inc. | New | 0.23% | +0.23 |
| SLNO Soleno Therapeutics Inc. | New | 0.21% | +0.21 |
| ETNB 89BIO Inc. | New | 0.16% | +0.16 |
| LLY Eli Lilly & Co. | Add +1.8% | 4.26% | +0.16 |
| AKRO Akero Therapeutics Inc. | Add +1.4% | 1.00% | +0.13 |
| PHVS Pharvaris NV | Add +2.4% | 0.57% | +0.11 |
| JSPR Jasper Therapeutics Inc. | Add +0.9% | 0.38% | +0.10 |
| CRNX Crinetics Pharmaceuticals Inc. | Add +1.6% | 0.57% | +0.09 |
| NGNE Neurogene Inc. | New | 0.08% | +0.08 |
| ATEC Alphatec Holdings Inc. | New | 0.07% | +0.07 |
| PLRX Pliant Therapeutics Inc. | Add +5.1% | 0.20% | +0.06 |
| ALNY Alnylam Pharmaceuticals Inc. | Add +2.5% | 2.30% | +0.06 |
| BEAM Beam Therapeutics Inc. | Add +0.9% | 0.24% | +0.04 |
| LENZ Lenz Therapeutics Inc. | New | 0.03% | +0.03 |
| NMRA Neumora Therapeutics Inc. | Add +15.3% | 0.39% | +0.03 |
| LUNG Pulmonx Corp. | Add +11.7% | 0.20% | +0.01 |
| MREO Mereo Biopharma Group PL-ADR | Add +0.7% | 1.28% | +0.00 |
| FOCL Edap TMS SA -ADR | Add +1.5% | 0.13% | +0.00 |
| PRTA Prothena Corp. PLC | Add +3.1% | 0.34% | −0.00 |
| MERSANA THERAPEUTICS INC | Add +12.6% | 0.19% | −0.00 |
| NVRO Nevro LLC | Add +19.3% | 0.23% | −0.02 |
| CMPX Compass Therapeutics Inc. | Add +2.7% | 0.32% | −0.02 |
| BHVN Biohaven Ltd. | Add +1.8% | 0.18% | −0.02 |
| ADAPY Adaptimmune Therapeutics-ADR | Add +2.4% | 0.05% | −0.02 |
| SMMT Summit Therapeutics Inc. | Add +1.4% | 0.72% | −0.02 |
| CLDX Celldex Therapeutics Inc. | Add +10.7% | 1.18% | −0.04 |
| CGEM Cullinan Therapeutics Inc. | Add +0.7% | 0.34% | −0.06 |
| DYN Dyne Therapeutics Inc. | Add +2.9% | 0.43% | −0.11 |
| CATX Perspective Therapeutics Inc. | Add +7.2% | 0.05% | −0.13 |
| OSCR Oscar Health Inc. Class A | Add +3.8% | 0.54% | −0.16 |
| LEGN Legend Biotech Corp.-ADR | Add +0.6% | 0.64% | −0.17 |
| INZY Inozyme Pharma Inc. | Add +1.6% | 0.41% | −0.24 |
| GPCR Structure Therapeutics Inc. | Add +1.6% | 1.12% | −0.40 |
| APLT Applied Therapeutics Inc. | Add +9.8% | 0.06% | −0.42 |
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 |