Rock Springs Capital Management LP

In its 13F for Q3 2024 (holdings as of September 30, 2024, filed November 14, 2024), Rock Springs Capital Management LP reported 106 stock positions worth $3.1 billion. Its top holding was Unitedhealth (UNH) at 5.6% of the portfolio, followed by Intuitive Surgical (ISRG, 4.3%) and Argenx SE - ADR (ARGX, 4.1%). Compared with Q2 2024, it opened 6 new positions, sold out of 6, added to 34 and reduced 30. The biggest buy was Unitedhealth (UNH, shares +7%) and the biggest sale Blueprint Medicines (BPMC, shares −69%).

Most Recent 13F
Q2 2026
Location
Baltimore, MD
CIK
0001595725
Portfolio Value
$3.1B (Q3 2024)
SEC Filing
0001172661-24-004721 ↗ filed Nov 14, 2024

Holdings Value

0$1.0B$2.0B$3.0B$4.0B Q1 2024: $3.9B Q1 2024 Q2 2024: $3.3B Q2 2024 Q3 2024: $3.1B $3.1B Q3 2024 Q4 2024: $2.6B Q4 2024 Q1 2025: $1.7B Q1 2025 Q2 2025: $1.6B Q2 2025 Q3 2025: $1.7B Q3 2025 Q4 2025: $1.9B Q4 2025 Q1 2026: $1.7B Q1 2026 Q2 2026: $2.0B Q2 2026

Holdings 106 stocks · $3.1B
UNH Unitedhealth Group Inc. 5.61% 294,250 $172.0M Add +7.0%
ISRG Intuitive Surgical Inc. 4.32% 270,000 $132.6M Reduce -9.6%
ARGX Argenx SE - ADR 4.13% 233,500 $126.6M Add +1.9%
LLY Eli Lilly & Co. 4.10% 142,000 $125.8M Add +16.9%
RARE Ultragenyx Pharmaceutical Inc. 3.58% 1,978,272 $109.9M Add +2.8%
NBIX Neurocrine Biosciences Inc. 3.53% 939,000 $108.2M Reduce -0.1%
EXAS Exact Sciences Corp. 2.55% 1,147,500 $78.2M Add +6.1%
BPMC Blueprint Medicines Corp. 2.32% 768,776 $71.1M Reduce -68.8%
ALNY Alnylam Pharmaceuticals Inc. 2.24% 250,000 $68.8M No change
TVTX Travere Therapeutics Inc. 2.14% 4,684,476 $65.5M Add +4.5%
RYTM Rhythm Pharmaceuticals Inc. 2.10% 1,228,093 $64.3M Reduce -4.1%
MIRM Mirum Pharmaceuticals Inc. 2.01% 1,580,488 $61.6M Reduce -10.8%
FRPT Freshpet Inc. 1.99% 446,500 $61.1M Reduce -7.0%
EVH Evolent Health Inc. Class A 1.91% 2,070,000 $58.5M Reduce -49.2%
MDGL Madrigal Pharmaceuticals Inc. 1.82% 263,062 $55.8M Add +7.2%
PHR Phreesia Inc. 1.70% 2,282,500 $52.0M Reduce -5.6%
XENE Xenon Pharmaceuticals Inc. 1.69% 1,316,477 $51.8M Add +3.4%
ACHC Acadia Healthcare Co. Inc. 1.68% 815,000 $51.7M Reduce -30.8%
PEN Penumbra Inc. 1.68% 265,000 $51.5M No change
WST West Pharmaceutical Services 1.64% 167,750 $50.4M Add +15.3%
INSM Insmed Inc. 1.63% 683,344 $49.9M Reduce -15.5%
KYMR Kymera Therapeutics Inc. 1.62% 1,049,386 $49.7M Reduce -9.8%
ASND Ascendis Pharma A/S 1.58% 325,000 $48.5M Add +12.1%
HUM Humana Inc. 1.53% 148,000 $46.9M Add +0.4%
GPCR Structure Therapeutics Inc. 1.52% 1,063,910 $46.7M Add +6.4%
RVMD Revolution Medicines Inc. 1.49% 1,009,945 $45.8M Add +7.1%
MRUS Merus NV 1.45% 892,549 $44.6M Reduce -10.8%
NUVL Nuvalent Inc. Class A 1.43% 429,994 $44.0M Add +68.0%
MREO Mereo Biopharma Group PL-ADR 1.28% 9,534,170 $39.2M Add +2.7%
BSX Boston Scientific Corp. 1.26% 460,000 $38.5M Reduce -43.7%
SRPT Sarepta Therapeutics Inc. 1.25% 307,500 $38.4M Add +8.3%
EW Edwards Lifesciences Corp. 1.24% 576,900 $38.1M Add +4.9%
CLDX Celldex Therapeutics Inc. 1.22% 1,103,778 $37.5M Reduce -21.1%
AGL Agilon Health Inc. 1.17% 9,096,800 $35.8M Add +2.2%
DXCM Dexcom Inc. 1.14% 524,000 $35.1M Add +4.8%
IMVT Immunovant Inc. 1.13% 1,221,309 $34.8M Add +3.0%
ZLAB Zai Lab Ltd.-ADR 1.04% 1,315,673 $31.8M Add +1.4%
PODD Insulet Corp. 1.02% 134,000 $31.2M Reduce -31.3%
AGIO Agios Pharmaceuticals Inc. 1.01% 699,389 $31.1M Reduce -33.0%
IRTC Irhythm Holdings Inc. 0.96% 397,500 $29.5M No change
ALGN Align Technology Inc. 0.95% 114,500 $29.1M Reduce -10.2%
BCRX Biocryst Pharmaceuticals Inc. 0.90% 3,622,358 $27.5M Add +0.1%
INSP Inspire Medical Systems Inc. 0.89% 130,000 $27.4M No change
AKRO Akero Therapeutics Inc. 0.87% 933,399 $26.8M Reduce -13.1%
AZTA Azenta Inc. 0.84% 532,500 $25.8M Reduce -23.5%
LEGN Legend Biotech Corp.-ADR 0.81% 508,932 $24.8M Add +0.6%
WRBY Warby Parker Inc. Class A 0.77% 1,439,050 $23.5M Reduce -30.8%
SMMT Summit Therapeutics Inc. 0.74% 1,040,000 $22.8M New
LFST Lifestance Health Group Inc. 0.71% 3,101,000 $21.7M Reduce -35.8%
OSCR Oscar Health Inc. Class A 0.70% 1,011,400 $21.5M Reduce -19.2%
INZY Inozyme Pharma Inc. 0.65% 3,802,883 $19.9M Add +2.8%
VERA Vera Therapeutics Inc. 0.55% 383,492 $17.0M Add +0.6%
DYN Dyne Therapeutics Inc. 0.54% 461,028 $16.6M No change
NVO Novo-Nordisk A/S-Spons ADR 0.51% 132,000 $15.7M Reduce -10.5%
ZBIO Zenas Biopharma Inc. 0.48% 878,667 $14.9M New
APLT Applied Therapeutics Inc. 0.48% 1,746,449 $14.8M Add +12.3%
CRNX Crinetics Pharmaceuticals Inc. 0.48% 289,400 $14.8M No change
PHVS Pharvaris NV 0.46% 756,931 $14.0M No change
FOLD Amicus Therapeutics Inc. 0.44% 1,250,280 $13.4M Add +2.6%
JNJ Johnson & Johnson 0.42% 80,000 $13.0M Reduce -52.9%
CGEM Cullinan Therapeutics Inc. 0.40% 736,914 $12.3M Add +11.9%
BCAX Bicara Therapeutics Inc. 0.37% 445,975 $11.4M New
ELVN Enliven Therapeutics Inc. 0.36% 428,571 $10.9M No change
NMRA Neumora Therapeutics Inc. 0.36% 828,101 $10.9M Add +9.0%
CYTK Cytokinetics Inc. 0.35% 206,108 $10.9M New
BMRN Biomarin Pharmaceutical Inc. 0.35% 151,000 $10.6M No change
PRTA Prothena Corp. PLC 0.34% 625,048 $10.5M No change
CMPX Compass Therapeutics Inc. 0.34% 5,629,239 $10.4M Add +2.1%
KRYS Krystal Biotech Inc. 0.33% 55,861 $10.2M Reduce -47.1%
AUPH Aurinia Pharmaceuticals Inc. 0.28% 1,179,740 $8.6M No change
JSPR Jasper Therapeutics Inc. 0.28% 459,088 $8.6M Add +13.5%
NVAX Novavax Inc. 0.27% 650,000 $8.2M Reduce -3.7%
XNCR Xencor Inc. 0.26% 401,013 $8.1M New
NVRO Nevro LLC filed as NEVRO CORP 0.25% 1,381,500 $7.7M No change
DVAX Dynavax Technologies Corp. 0.22% 605,013 $6.7M Reduce -53.2%
SWTX Springworks Therapeutics Inc. 0.21% 199,855 $6.4M No change
BHVN Biohaven Ltd. 0.21% 127,558 $6.4M No change
BEAM Beam Therapeutics Inc. 0.20% 249,923 $6.1M No change
PCRX Pacira Biosciences Inc. 0.20% 400,000 $6.0M Reduce -49.0%
NAMS Newamsterdam Pharma Co. NV 0.19% 353,319 $5.9M New
MERSANA THERAPEUTICS INC 0.19% 3,046,782 $5.8M No change
LUNG Pulmonx Corp. 0.19% 691,300 $5.7M Add +6.0%
ABOS Acumen Pharmaceuticals Inc. 0.19% 2,300,059 $5.7M No change
CATX Perspective Therapeutics Inc. 0.18% 414,396 $5.5M Add +3.3%
PLRX Pliant Therapeutics Inc. 0.14% 384,996 $4.3M No change
EPIX Essa Pharma Inc. 0.13% 677,005 $4.1M No change
FOCL Edap TMS SA -ADR 0.13% 1,568,000 $4.0M Add +6.3%
AUTL Autolus Therapeutics PLC 0.12% 1,032,988 $3.7M No change
MGNX Macrogenics Inc. 0.11% 1,053,647 $3.5M No change
CYPH Cypherpunk Technologies Inc. filed as LEAP THERAPEUTICS INC 0.11% 1,266,546 $3.3M No change
GOSS Gossamer Bio Inc. 0.10% 3,266,960 $3.2M No change
ACRS Aclaris Therapeutics Inc. 0.10% 2,753,495 $3.2M No change
XLO Xilio Therapeutics Inc. 0.08% 3,003,259 $2.4M No change
APLS Apellis Pharmaceuticals Inc. 0.08% 80,000 $2.3M Reduce -43.1%
ADAPY Adaptimmune Therapeutics-ADR 0.08% 2,425,468 $2.3M No change
SGMT Sagimet Biosciences Inc. Class A 0.07% 787,808 $2.2M No change
BMEA Biomea Fusion Inc. 0.06% 181,147 $1.8M No change
CGEN Compugen Ltd. 0.06% 989,990 $1.8M No change
VIGL Vigil Neuroscience Inc. 0.05% 471,958 $1.6M No change
SPRB Spruce Biosciences Inc. 0.04% 2,609,125 $1.2M No change
KRRO Korro Bio Inc. 0.04% 35,719 $1.2M No change
KYTX Kyverna Therapeutics Inc. 0.03% 178,963 $875K No change
ALLK Allakos LLC 0.03% 1,200,409 $784K No change
VINCERX PHARMA INC 0.02% 891,719 $638K No change
ACCD Accolade Inc. 0.02% 160,217 $617K Reduce -93.0%
TLPH Talphera Inc. 0.01% 316,460 $271K No change
Other holdings (3): bonds, preferreds, convertibles and warrants · $5.5M (not counted above)
SecurityClassShares / PrincipalValueChange
GOSSAMER BIO INC (GOSS 5 06/01/27) NOTE 5.000% 6/0 · principal 9,573,000$5.0MNo change
NEVRO CORP (NVRO 2.75 04/01/25) NOTE 2.750% 4/0 · principal 500,000$484KNo change
NUVB.WS Nuvation Bio Inc. -CW27 *W EXP 02/10/202 134,028$13KNo change

Total filed on the 13F, all lines: $3.1B.

Portfolio Sells Q2 2024 → Q3 2024
BPMC Blueprint Medicines Corp. Reduce -68.8% 2.32% −5.70
IDXX Idexx Laboratories Inc. Sold out 0.00% −1.76
ACHC Acadia Healthcare Co. Inc. Reduce -30.8% 1.68% −0.72
BSX Boston Scientific Corp. Reduce -43.7% 1.26% −0.65
PCRX Pacira Biosciences Inc. Reduce -49.0% 0.20% −0.48
EVH Evolent Health Inc. Class A Reduce -49.2% 1.91% −0.45
IMCR Immunocore Holdings PLC-ADR Sold out 0.00% −0.43
NBIX Neurocrine Biosciences Inc. Reduce -0.1% 3.53% −0.39
OLK Olink Holding AB - ADR Sold out 0.00% −0.39
CRL Charles River Laboratories Sold out 0.00% −0.38
AGIO Agios Pharmaceuticals Inc. Reduce -33.0% 1.01% −0.35
CLDX Celldex Therapeutics Inc. Reduce -21.1% 1.22% −0.34
MRUS Merus NV Reduce -10.8% 1.45% −0.34
JNJ Johnson & Johnson Reduce -52.9% 0.42% −0.33
AZTA Azenta Inc. Reduce -23.5% 0.84% −0.27
KRYS Krystal Biotech Inc. Reduce -47.1% 0.33% −0.26
WRBY Warby Parker Inc. Class A Reduce -30.8% 0.77% −0.24
ACCD Accolade Inc. Reduce -93.0% 0.02% −0.23
DVAX Dynavax Technologies Corp. Reduce -53.2% 0.22% −0.22
PODD Insulet Corp. Reduce -31.3% 1.02% −0.17
FULC Fulcrum Therapeutics Inc. Sold out 0.00% −0.14
MLYS Mineralys Therapeutics Inc. Sold out 0.00% −0.13
NVO Novo-Nordisk A/S-Spons ADR Reduce -10.5% 0.51% −0.12
APLS Apellis Pharmaceuticals Inc. Reduce -43.1% 0.08% −0.09
INSM Insmed Inc. Reduce -15.5% 1.63% −0.01
LFST Lifestance Health Group Inc. Reduce -35.8% 0.71% −0.01
NVAX Novavax Inc. Reduce -3.7% 0.27% +0.01
ALGN Align Technology Inc. Reduce -10.2% 0.95% +0.02
OSCR Oscar Health Inc. Class A Reduce -19.2% 0.70% +0.10
AKRO Akero Therapeutics Inc. Reduce -13.1% 0.87% +0.11
FRPT Freshpet Inc. Reduce -7.0% 1.99% +0.11
PHR Phreesia Inc. Reduce -5.6% 1.70% +0.14
MIRM Mirum Pharmaceuticals Inc. Reduce -10.8% 2.01% +0.18
ISRG Intuitive Surgical Inc. Reduce -9.6% 4.32% +0.31
RYTM Rhythm Pharmaceuticals Inc. Reduce -4.1% 2.10% +0.51
KYMR Kymera Therapeutics Inc. Reduce -9.8% 1.62% +0.57

Portfolio Buys Q2 2024 → Q3 2024
UNH Unitedhealth Group Inc. Add +7.0% 5.61% +1.37
RARE Ultragenyx Pharmaceutical Inc. Add +2.8% 3.58% +1.19
EXAS Exact Sciences Corp. Add +6.1% 2.55% +1.17
ARGX Argenx SE - ADR Add +1.9% 4.13% +1.14
TVTX Travere Therapeutics Inc. Add +4.5% 2.14% +1.02
NUVL Nuvalent Inc. Class A Add +68.0% 1.43% +0.85
LLY Eli Lilly & Co. Add +16.9% 4.10% +0.77
SMMT Summit Therapeutics Inc. New 0.74% +0.74
ZBIO Zenas Biopharma Inc. New 0.48% +0.48
RVMD Revolution Medicines Inc. Add +7.1% 1.49% +0.39
ASND Ascendis Pharma A/S Add +12.1% 1.58% +0.39
BCAX Bicara Therapeutics Inc. New 0.37% +0.37
CYTK Cytokinetics Inc. New 0.35% +0.35
ZLAB Zai Lab Ltd.-ADR Add +1.4% 1.04% +0.35
GPCR Structure Therapeutics Inc. Add +6.4% 1.52% +0.33
MREO Mereo Biopharma Group PL-ADR Add +2.7% 1.28% +0.27
APLT Applied Therapeutics Inc. Add +12.3% 0.48% +0.26
XNCR Xencor Inc. New 0.26% +0.26
BCRX Biocryst Pharmaceuticals Inc. Add +0.1% 0.90% +0.22
WST West Pharmaceutical Services Add +15.3% 1.64% +0.19
NAMS Newamsterdam Pharma Co. NV New 0.19% +0.19
IMVT Immunovant Inc. Add +3.0% 1.13% +0.19
XENE Xenon Pharmaceuticals Inc. Add +3.4% 1.69% +0.19
CMPX Compass Therapeutics Inc. Add +2.1% 0.34% +0.17
INZY Inozyme Pharma Inc. Add +2.8% 0.65% +0.15
VERA Vera Therapeutics Inc. Add +0.6% 0.55% +0.14
LEGN Legend Biotech Corp.-ADR Add +0.6% 0.81% +0.13
NMRA Neumora Therapeutics Inc. Add +9.0% 0.36% +0.13
FOLD Amicus Therapeutics Inc. Add +2.6% 0.44% +0.07
LUNG Pulmonx Corp. Add +6.0% 0.19% +0.06
CATX Perspective Therapeutics Inc. Add +3.3% 0.18% +0.06
CGEM Cullinan Therapeutics Inc. Add +11.9% 0.40% +0.05
JSPR Jasper Therapeutics Inc. Add +13.5% 0.28% +0.00
SRPT Sarepta Therapeutics Inc. Add +8.3% 1.25% −0.11
FOCL Edap TMS SA -ADR Add +6.3% 0.13% −0.11
HUM Humana Inc. Add +0.4% 1.53% −0.14
MDGL Madrigal Pharmaceuticals Inc. Add +7.2% 1.82% −0.26
EW Edwards Lifesciences Corp. Add +4.9% 1.24% −0.30
DXCM Dexcom Inc. Add +4.8% 1.14% −0.57
AGL Agilon Health Inc. Add +2.2% 1.17% −0.60

Options Activity Q2 2024 → Q3 2024
BPMC Blueprint Medicines Corp. call Sold out 57,000 $6.1Mbefore exit
GPCR Structure Therapeutics Inc. call Sold out 65,600 $2.6Mbefore exit

Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.

Notes & Other Activity Q2 2024 → Q3 2024
TRAVERE THERAPEUTICS INC (TVTX 2.5 09/15/25) NOTE 2.500% 9/1 · principal Sold out 3,250,000 $2.9Mbefore exit

Bonds, preferreds, convertibles and warrants; not part of the stock holdings or percentages above.

All Filings

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 104$2.0BRVMD, TVTX, LLY, MDGL, MIRM
Q1 2026 100$1.7BRVMD, LLY, MDGL, MIRM, ARGX
Q4 2025 96$1.9BLLY, RVMD, ARGX, TVTX, MDGL
Q3 2025 90$1.7BARGX, LLY, RYTM, MDGL, RVMD
Q2 2025 91$1.6BARGX, LLY, MRUS, RYTM, INSM
Q1 2025 94$1.7BARGX, LLY, BPMC, MDGL, UNH
Q4 2024 104$2.6BARGX, ISRG, LLY, NBIX, BPMC
Q3 2024 106$3.1BUNH, ISRG, ARGX, LLY, RARE
Q2 2024 106$3.3BBPMC, UNH, ISRG, NBIX, LLY
Q1 2024 108$3.9BBPMC, IMCR, NBIX, EVH, ISRG