Rock Springs Capital Management LP

In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 15, 2026), Rock Springs Capital Management LP reported 100 stock positions worth $1.7 billion. Its top holding was Revolution Medicines (RVMD) at 6.9% of the portfolio, followed by Eli Lilly (LLY, 5.4%) and Madrigal Pharmaceuticals (MDGL, 5.3%). Compared with Q4 2025, it opened 9 new positions, sold out of 5, added to 39 and reduced 24. The biggest buy was Mirum Pharmaceuticals (MIRM, shares +6%) and the biggest sale an exit from Exact Sciences (EXAS).

Most Recent 13F
Q2 2026
Location
Baltimore, MD
CIK
0001595725
Portfolio Value
$1.7B (Q1 2026)
SEC Filing
0001172661-26-002225 ↗ filed May 15, 2026

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 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 $1.7B Q1 2026 Q2 2026: $2.0B Q2 2026

Holdings 100 stocks · $1.7B
RVMD Revolution Medicines Inc. 6.93% 1,209,465 $117.6M Reduce -9.4%
LLY Eli Lilly & Co. 5.35% 98,700 $90.8M Reduce -6.4%
MDGL Madrigal Pharmaceuticals Inc. 5.28% 170,999 $89.5M Add +22.5%
MIRM Mirum Pharmaceuticals Inc. 4.42% 811,294 $74.9M Add +6.4%
ARGX Argenx SE - ADR 4.24% 98,500 $71.9M Reduce -4.6%
RYTM Rhythm Pharmaceuticals Inc. 3.54% 689,748 $60.0M Reduce -0.8%
INSM Insmed Inc. 3.03% 314,300 $51.4M Reduce -1.6%
ASND Ascendis Pharma A/S 2.62% 194,000 $44.4M Reduce -4.7%
XENE Xenon Pharmaceuticals Inc. 2.62% 763,020 $44.4M Reduce -3.1%
TVTX Travere Therapeutics Inc. 2.59% 1,477,954 $43.9M Reduce -33.1%
KYMR Kymera Therapeutics Inc. 2.44% 496,871 $41.4M No change
PEN Penumbra Inc. 2.33% 120,500 $39.6M No change
ISRG Intuitive Surgical Inc. 2.23% 82,000 $37.8M No change
SRRK Scholar Rock Holding Corp. 2.14% 739,816 $36.4M Add +0.9%
ELVN Enliven Therapeutics Inc. 1.91% 826,500 $32.4M Add +3.5%
BSX Boston Scientific Corp. 1.91% 515,300 $32.3M Add +29.1%
IRTC Irhythm Holdings Inc. 1.82% 261,750 $30.9M Add +11.4%
GPCR Structure Therapeutics Inc. 1.82% 640,217 $30.9M Reduce -14.4%
AGIO Agios Pharmaceuticals Inc. 1.59% 799,163 $27.0M No change
RARE Ultragenyx Pharmaceutical Inc. 1.50% 1,218,773 $25.5M Reduce -3.8%
ALNY Alnylam Pharmaceuticals Inc. 1.44% 74,000 $24.5M Add +3.9%
COGT Cogent Biosciences Inc. 1.42% 624,155 $24.0M Reduce -26.5%
THC Tenet Healthcare Corp. 1.39% 125,000 $23.6M No change
DXCM Dexcom Inc. 1.32% 355,600 $22.3M Add +2.4%
CLDX Celldex Therapeutics Inc. 1.22% 650,270 $20.6M Reduce -6.1%
VERA Vera Therapeutics Inc. 1.19% 503,585 $20.3M Reduce -11.4%
NBIX Neurocrine Biosciences Inc. 1.17% 150,450 $19.8M Add +19.9%
ACLX Arcellx Inc. 1.15% 169,859 $19.5M No change
NAMS Newamsterdam Pharma Co. NV 1.11% 588,794 $18.8M Add +5.7%
PHVS Pharvaris NV 1.07% 645,533 $18.2M Add +3.5%
ERAS Erasca Inc. 1.05% 1,103,469 $17.9M Add +15.9%
DYN Dyne Therapeutics Inc. 1.04% 972,198 $17.6M Add +6.5%
CMPX Compass Therapeutics Inc. 1.03% 3,305,308 $17.5M Reduce -15.8%
ACRS Aclaris Therapeutics Inc. 0.99% 4,472,650 $16.8M Add +0.4%
TARS Tarsus Pharmaceuticals Inc. 0.93% 225,179 $15.8M Reduce -13.5%
MMED Minimed Group Inc. 0.93% 1,055,000 $15.7M New
ZLAB Zai Lab Ltd.-ADR 0.90% 814,707 $15.3M Add +0.4%
UNH Unitedhealth Group Inc. 0.85% 53,000 $14.3M Add +29.9%
CNTA Centessa Pharmaceuticals Ltd. 0.82% 351,828 $14.0M Add +8.6%
HTFL Heartflow Inc. 0.82% 572,500 $13.9M Add +106.2%
ARDX Ardelyx Inc. 0.81% 2,299,473 $13.8M No change
SMMT Summit Therapeutics Inc. 0.79% 710,000 $13.5M No change
AZTA Azenta Inc. 0.71% 569,100 $12.0M No change
MLYS Mineralys Therapeutics Inc. 0.70% 439,751 $11.9M Add +2.8%
DHR Danaher Corp. 0.69% 61,500 $11.7M No change
PTCT PTC Therapeutics Inc. 0.65% 161,798 $11.0M Add +161.5%
CAI Caris Life Sciences Inc. 0.59% 563,000 $10.1M Reduce -18.1%
ZBIO Zenas Biopharma Inc. 0.58% 502,077 $9.8M No change
BCAX Bicara Therapeutics Inc. 0.57% 489,095 $9.7M Add +14.0%
BBIO Bridgebio Pharma Inc. 0.56% 128,250 $9.5M Add +23.9%
SLNO Soleno Therapeutics Inc. 0.51% 257,253 $8.6M Add +4.1%
MBX MBX Biosciences Inc. 0.51% 287,967 $8.6M Add +1.9%
TNGX Tango Therapeutics Inc. 0.48% 386,915 $8.1M No change
REGN Regeneron Pharmaceuticals 0.46% 10,100 $7.8M No change
IMNM Immunome Inc. 0.45% 347,666 $7.6M No change
AMLX Amylyx Pharmaceuticals Inc. 0.41% 499,764 $6.9M No change
OMDA Omada Health Inc. 0.40% 541,000 $6.8M Reduce -26.9%
INSP Inspire Medical Systems Inc. 0.40% 131,800 $6.8M Add +0.6%
APLS Apellis Pharmaceuticals Inc. 0.39% 162,750 $6.5M Add +8.1%
ALKS Alkermes PLC 0.38% 183,986 $6.5M Add +32.1%
EVH Evolent Health Inc. Class A 0.36% 2,675,000 $6.1M No change
INDV Indivior Pharmaceuticals Inc. 0.36% 200,000 $6.1M Add +90.3%
TERN Terns Pharmaceuticals Inc. 0.35% 113,748 $6.0M Add +4.9%
FOCL Edap TMS SA -ADR 0.30% 1,378,000 $5.1M Add +7.1%
JANX Janux Therapeutics Inc. 0.30% 367,009 $5.1M Add +2.3%
PHR Phreesia Inc. 0.30% 600,400 $5.0M Reduce -31.5%
TMO Thermo Fisher Scientific Inc. 0.29% 10,000 $4.9M No change
SYK Stryker Corp. 0.29% 14,800 $4.9M New
SION Sionna Therapeutics Inc. 0.23% 99,429 $4.0M No change
RCUS Arcus Biosciences Inc. 0.23% 180,000 $3.9M No change
XBI SS SPDR S&P Biotech ETF 0.23% 30,000 $3.8M Reduce -86.5%
ATEC Alphatec Holdings Inc. 0.22% 350,000 $3.8M Add +15.7%
PCVX Vaxcyte Inc. 0.21% 60,250 $3.5M Add +28.2%
EYPT Eyepoint Inc. 0.20% 258,739 $3.3M No change
NVO Novo-Nordisk A/S-Spons ADR 0.19% 90,000 $3.3M New
OCUL Ocular Therapeutix Inc. 0.19% 383,716 $3.3M Add +11.0%
VKTX Viking Therapeutics Inc. 0.18% 96,000 $3.1M New
CYTK Cytokinetics Inc. 0.18% 45,364 $3.0M Add +26.5%
IPSC Century Therapeutics Inc. 0.17% 1,304,347 $2.9M New
CVS CVS Health Corp. 0.17% 40,000 $2.9M New
ROIV Roivant Sciences Ltd. 0.16% 97,000 $2.7M Add +9.3%
TLPH Talphera Inc. 0.16% 3,589,186 $2.7M No change
OLMA Olema Pharmaceuticals Inc. 0.15% 170,378 $2.5M Add +73.4%
SGRY Surgery Partners Inc. 0.15% 208,000 $2.5M Reduce -32.9%
LENZ Lenz Therapeutics Inc. 0.14% 257,460 $2.4M No change
EW Edwards Lifesciences Corp. 0.14% 28,900 $2.3M Reduce -65.0%
DNTH Dianthus Therapeutics Inc. 0.13% 26,757 $2.2M New
NGNE Neurogene Inc. 0.12% 104,339 $2.1M No change
AGL Agilon Health Inc. 0.12% 260,000 $2.1M No change
CORT Corcept Therapeutics Inc. 0.12% 50,250 $2.0M No change
ACHC Acadia Healthcare Co. Inc. 0.10% 75,500 $1.8M Reduce -37.1%
TEVA Teva Pharmaceutical-SP ADR 0.08% 45,500 $1.4M No change
MLTX Moonlake Immunotherapeutics 0.07% 61,700 $1.2M No change
JAZZ Jazz Pharmaceuticals PLC 0.06% 5,750 $1.1M Add +228.6%
JSPR Jasper Therapeutics Inc. 0.06% 1,100,726 $964K No change
LEGN Legend Biotech Corp.-ADR 0.04% 40,500 $733K Add +19.8%
GOSS Gossamer Bio Inc. 0.03% 1,609,492 $529K Reduce -50.7%
FOLD Amicus Therapeutics Inc. 0.02% 21,062 $305K Reduce -98.9%
ORKA Oruka Therapeutics Inc. 0.01% 4,123 $202K New
BCRX Biocryst Pharmaceuticals Inc. 0.01% 12,600 $120K New

Portfolio Sells Q4 2025 → Q1 2026
EXAS Exact Sciences Corp. Sold out 0.00% −3.15
CDTX Cidara Therapeutics Inc. Sold out 0.00% −2.33
TVTX Travere Therapeutics Inc. Reduce -33.1% 2.59% −1.76
FOLD Amicus Therapeutics Inc. Reduce -98.9% 0.02% −1.40
XBI SS SPDR S&P Biotech ETF Reduce -86.5% 0.23% −1.17
GPCR Structure Therapeutics Inc. Reduce -14.4% 1.82% −0.86
GOSS Gossamer Bio Inc. Reduce -50.7% 0.03% −0.49
LLY Eli Lilly & Co. Reduce -6.4% 5.35% −0.48
PHR Phreesia Inc. Reduce -31.5% 0.30% −0.47
RAPT Rapt Therapeutics Inc. Sold out 0.00% −0.37
CAI Caris Life Sciences Inc. Reduce -18.1% 0.59% −0.36
RYTM Rhythm Pharmaceuticals Inc. Reduce -0.8% 3.54% −0.29
VERA Vera Therapeutics Inc. Reduce -11.4% 1.19% −0.29
ARGX Argenx SE - ADR Reduce -4.6% 4.24% −0.23
MRSN Mersana Therapeutics Inc. Sold out 0.00% −0.23
EW Edwards Lifesciences Corp. Reduce -65.0% 0.14% −0.23
TBPH Theravance Biopharma Inc. Sold out 0.00% −0.20
OMDA Omada Health Inc. Reduce -26.9% 0.40% −0.20
TARS Tarsus Pharmaceuticals Inc. Reduce -13.5% 0.93% −0.17
COGT Cogent Biosciences Inc. Reduce -26.5% 1.42% −0.14
SGRY Surgery Partners Inc. Reduce -32.9% 0.15% −0.10
CMPX Compass Therapeutics Inc. Reduce -15.8% 1.03% −0.06
RARE Ultragenyx Pharmaceutical Inc. Reduce -3.8% 1.50% +0.00
ACHC Acadia Healthcare Co. Inc. Reduce -37.1% 0.10% +0.02
INSM Insmed Inc. Reduce -1.6% 3.03% +0.17
CLDX Celldex Therapeutics Inc. Reduce -6.1% 1.22% +0.25
ASND Ascendis Pharma A/S Reduce -4.7% 2.62% +0.38
XENE Xenon Pharmaceuticals Inc. Reduce -3.1% 2.62% +0.80
RVMD Revolution Medicines Inc. Reduce -9.4% 6.93% +1.46

Portfolio Buys Q4 2025 → Q1 2026
MIRM Mirum Pharmaceuticals Inc. Add +6.4% 4.42% +1.32
ELVN Enliven Therapeutics Inc. Add +3.5% 1.91% +1.28
MDGL Madrigal Pharmaceuticals Inc. Add +22.5% 5.28% +1.09
MMED Minimed Group Inc. New 0.93% +0.93
ERAS Erasca Inc. Add +15.9% 1.05% +0.87
SRRK Scholar Rock Holding Corp. Add +0.9% 2.14% +0.48
PTCT PTC Therapeutics Inc. Add +161.5% 0.65% +0.41
CNTA Centessa Pharmaceuticals Ltd. Add +8.6% 0.82% +0.41
HTFL Heartflow Inc. Add +106.2% 0.82% +0.40
ACRS Aclaris Therapeutics Inc. Add +0.4% 0.99% +0.30
SYK Stryker Corp. New 0.29% +0.29
NBIX Neurocrine Biosciences Inc. Add +19.9% 1.17% +0.25
BCAX Bicara Therapeutics Inc. Add +14.0% 0.57% +0.20
NVO Novo-Nordisk A/S-Spons ADR New 0.19% +0.19
APLS Apellis Pharmaceuticals Inc. Add +8.1% 0.39% +0.19
PHVS Pharvaris NV Add +3.5% 1.07% +0.18
VKTX Viking Therapeutics Inc. New 0.18% +0.18
ALKS Alkermes PLC Add +32.1% 0.38% +0.18
IPSC Century Therapeutics Inc. New 0.17% +0.17
CVS CVS Health Corp. New 0.17% +0.17
ZLAB Zai Lab Ltd.-ADR Add +0.4% 0.90% +0.17
INDV Indivior Pharmaceuticals Inc. Add +90.3% 0.36% +0.17
BBIO Bridgebio Pharma Inc. Add +23.9% 0.56% +0.15
UNH Unitedhealth Group Inc. Add +29.9% 0.85% +0.15
DNTH Dianthus Therapeutics Inc. New 0.13% +0.13
DXCM Dexcom Inc. Add +2.4% 1.32% +0.13
TERN Terns Pharmaceuticals Inc. Add +4.9% 0.35% +0.13
DYN Dyne Therapeutics Inc. Add +6.5% 1.04% +0.12
NAMS Newamsterdam Pharma Co. NV Add +5.7% 1.11% +0.10
PCVX Vaxcyte Inc. Add +28.2% 0.21% +0.09
FOCL Edap TMS SA -ADR Add +7.1% 0.30% +0.08
ROIV Roivant Sciences Ltd. Add +9.3% 0.16% +0.06
CYTK Cytokinetics Inc. Add +26.5% 0.18% +0.06
JAZZ Jazz Pharmaceuticals PLC Add +228.6% 0.06% +0.05
MBX MBX Biosciences Inc. Add +1.9% 0.51% +0.05
JANX Janux Therapeutics Inc. Add +2.3% 0.30% +0.05
OLMA Olema Pharmaceuticals Inc. Add +73.4% 0.15% +0.02
ORKA Oruka Therapeutics Inc. New 0.01% +0.01
BCRX Biocryst Pharmaceuticals Inc. New 0.01% +0.01
LEGN Legend Biotech Corp.-ADR Add +19.8% 0.04% +0.01
ALNY Alnylam Pharmaceuticals Inc. Add +3.9% 1.44% −0.02
OCUL Ocular Therapeutix Inc. Add +11.0% 0.19% −0.02
BSX Boston Scientific Corp. Add +29.1% 1.91% −0.05
SLNO Soleno Therapeutics Inc. Add +4.1% 0.51% −0.08
MLYS Mineralys Therapeutics Inc. Add +2.8% 0.70% −0.10
ATEC Alphatec Holdings Inc. Add +15.7% 0.22% −0.10
INSP Inspire Medical Systems Inc. Add +0.6% 0.40% −0.22
IRTC Irhythm Holdings Inc. Add +11.4% 1.82% −0.33

Options Activity Q4 2025 → Q1 2026
NAMS Newamsterdam Pharma Co. NV call Sold out 31,600 $1.1Mbefore exit

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

Notes & Other Activity Q4 2025 → Q1 2026
GOSSAMER BIO INC (GOSS 5 06/01/27) NOTE 5.000% 6/0 · principal Sold out 9,573,000 $6.6Mbefore exit
NUVB.WS Nuvation Bio Inc. -CW27 *W EXP 02/10/202 Sold out 134,028 $44Kbefore 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