Rock Springs Capital Management LP
Net seller this quarter
$2.05B
104
-$9.82M
44.0%
Holdings
| Company | Value | % of portfolio | % of company | POSITION CHANGE qoq % | First reported |
|---|---|---|---|---|---|
| Q2 2026 | |||||
 RVMD | $207M | 10.10% | 0.52% | -8.6% | Q1 2023 |
 TVTX | $124M | 6.04% | 2.31% | +47.4% | Q4 2020 |
 LLY | $118M | 5.78% | 0.01% | Not reported | Q1 2015 |
 MDGL | $94M | 4.59% | 0.76% | +2.3% | Q3 2016 |
 MIRM | $93.4M | 4.56% | 1.23% | -1.6% | Q3 2019 |
 RYTM | $76.9M | 3.75% | 1.01% | +0.4% | Q4 2017 |
 KYMR | $52M | 2.54% | 0.55% | -8.8% | Q3 2020 |
 ARGX | $48.9M | 2.39% | 0.09% | -46.5% | Q2 2018 |
 ASND | $45M | 2.20% | 0.27% | -13.0% | Q1 2015 |
 XENE | $41.3M | 2.01% | 0.71% | -10.4% | Q1 2020 |
 SRRK | $39.3M | 1.92% | 0.59% | -3.3% | Q4 2024 |
 INSM | $38.6M | 1.88% | 0.17% | +15.2% | Q1 2015 |
 PEN | $36.5M | 1.78% | 0.29% | -3.9% | Q3 2015 |
 GPCR | $34.4M | 1.68% | 0.30% | 0.0% | Q4 2023 |
 RARE | $32.3M | 1.58% | 0.98% | -20.6% | Q1 2014 |
 IRTC | $32.1M | 1.57% | 0.82% | +3.0% | Q3 2017 |
 ISRG | $30.4M | 1.48% | 0.02% | -6.8% | Q4 2013 |
 AGL | $28.1M | 1.37% | 1.56% | +1.0% | Q2 2021 |
 UNH | $26.5M | 1.29% | 0.01% | +20.3% | Q4 2013 |
 CLDX | $26M | 1.27% | 0.89% | +7.5% | Q1 2022 |
 ERAS | $25.7M | 1.25% | 0.45% | +27.1% | Q4 2025 |
 NBIX | $24.4M | 1.19% | 0.14% | -3.8% | Q1 2014 |
 ELVN | $23.6M | 1.15% | 0.63% | -43.8% | Q1 2024 |
 THC | $23.4M | 1.14% | 0.15% | Not reported | Q4 2024 |
 DXCM | $23.1M | 1.13% | 0.09% | -3.5% | Q1 2021 |
 ACRS | $22.9M | 1.12% | 3.10% | -3.2% | Q4 2015 |
 MMED | $22.7M | 1.11% | 0.54% | +44.1% | Q1 2026 |
 BSX | $22.6M | 1.10% | 0.04% | +2.6% | Q2 2018 |
 PHVS | $22.4M | 1.09% | 0.99% | +0.4% | Q1 2024 |
 AVLN | $21.8M | 1.07% | 1.50% | New | Q2 2026 |
 COAG | $21.1M | 1.03% | 1.23% | New | Q2 2026 |
 DYN | $20.9M | 1.02% | 0.57% | -3.1% | Q1 2024 |
 ALNY | $20.1M | 0.98% | 0.05% | -9.8% | Q2 2017 |
 COGT | $20M | 0.97% | 0.30% | -17.3% | Q2 2025 |
 AGIO | $19.8M | 0.96% | 0.89% | -33.4% | Q1 2019 |
 NAMS | $19.7M | 0.96% | 0.50% | -1.0% | Q3 2024 |
 VERA | $18.3M | 0.90% | 0.60% | -15.1% | Q1 2024 |
 TARS | $17.4M | 0.85% | 0.64% | +23.1% | Q4 2024 |
 HTFL | $16.8M | 0.82% | 0.66% | +0.2% | Q3 2025 |
 MBX | $16.5M | 0.80% | 0.62% | +3.6% | Q3 2025 |
 CYTK | $16M | 0.78% | 0.15% | +314.4% | Q2 2020 |
| BCAX | $15.9M | 0.78% | 0.81% | +9.4% | Q3 2024 |
 PBLS | $15.8M | 0.77% | 0.47% | New | Q2 2026 |
 ZLAB | $15.5M | 0.76% | 0.07% | Not reported | Q3 2017 |
 DHR | $14.5M | 0.71% | 0.01% | +24.1% | Q3 2014 |
 TNGX | $14.3M | 0.70% | 0.27% | +18.0% | Q4 2025 |
 EVH | $13.6M | 0.66% | 2.22% | -6.5% | Q1 2021 |
 PTCT | $13.2M | 0.65% | 0.19% | +0.3% | Q1 2015 |
 MLYS | $13.1M | 0.64% | 0.55% | +10.3% | Q1 2023 |
 ZBIO | $12.7M | 0.62% | 0.79% | Not reported | Q3 2024 |
| Q1 2026 | |||||
| RVMD | $118M | 6.93% | 0.60% | -9.4% | Q1 2023 |
| LLY | $90.8M | 5.35% | 0.01% | -6.4% | Q1 2015 |
| MDGL | $89.5M | 5.28% | 0.74% | +22.5% | Q3 2016 |
| MIRM | $74.9M | 4.42% | 1.33% | +6.4% | Q3 2019 |
| ARGX | $71.9M | 4.24% | 0.16% | -4.6% | Q2 2018 |
| RYTM | $60M | 3.54% | 1.01% | -0.8% | Q4 2017 |
| INSM | $51.4M | 3.03% | 0.15% | -1.6% | Q1 2015 |
| ASND | $44.4M | 2.62% | 0.31% | -4.7% | Q1 2015 |
| XENE | $44.4M | 2.62% | 0.79% | -3.1% | Q1 2020 |
| TVTX | $43.9M | 2.59% | 1.60% | -33.1% | Q4 2020 |
| KYMR | $41.4M | 2.44% | 0.60% | Not reported | Q3 2020 |
| PEN | $39.6M | 2.33% | 0.31% | Not reported | Q3 2015 |
| ISRG | $37.8M | 2.23% | 0.02% | Not reported | Q4 2013 |
| SRRK | $36.4M | 2.14% | 0.62% | +0.9% | Q4 2024 |
| ELVN | $32.4M | 1.91% | 1.36% | +3.5% | Q1 2024 |
| BSX | $32.3M | 1.91% | 0.03% | +29.1% | Q2 2018 |
| IRTC | $30.9M | 1.82% | 0.80% | +11.4% | Q3 2017 |
| GPCR | $30.9M | 1.82% | 0.30% | -14.4% | Q4 2023 |
| AGIO | $27M | 1.59% | 1.35% | Not reported | Q1 2019 |
| RARE | $25.5M | 1.50% | 1.24% | -3.8% | Q1 2014 |
| ALNY | $24.5M | 1.44% | 0.06% | +3.9% | Q2 2017 |
| COGT | $24M | 1.42% | 0.37% | -26.5% | Q2 2025 |
| THC | $23.6M | 1.39% | 0.14% | Not reported | Q4 2024 |
| DXCM | $22.3M | 1.32% | 0.09% | +2.4% | Q1 2021 |
| CLDX | $20.6M | 1.22% | 0.98% | -6.1% | Q1 2022 |
| VERA | $20.3M | 1.19% | 0.79% | -11.4% | Q1 2024 |
| NBIX | $19.8M | 1.17% | 0.15% | +19.9% | Q1 2014 |
| ACLX | $19.5M | 1.15% | 0.29% | Not reported | Q2 2025 |
| NAMS | $18.8M | 1.11% | 0.50% | +5.7% | Q3 2024 |
| PHVS | $18.2M | 1.07% | 0.99% | +3.6% | Q1 2024 |
| ERAS | $17.9M | 1.05% | 0.36% | +16.0% | Q4 2025 |
| DYN | $17.6M | 1.04% | 0.59% | +6.5% | Q1 2024 |
 CMPX | $17.5M | 1.03% | 1.84% | -15.8% | Q4 2021 |
| ACRS | $16.8M | 0.99% | 3.20% | +0.4% | Q4 2015 |
| TARS | $15.8M | 0.93% | 0.52% | -13.5% | Q4 2024 |
| MMED | $15.7M | 0.93% | Not reported | New | Q1 2026 |
| ZLAB | $15.3M | 0.90% | 0.07% | +0.4% | Q3 2017 |
| UNH | $14.3M | 0.85% | 0.01% | +29.9% | Q4 2013 |
| CNTA | $14M | 0.82% | 0.23% | +8.6% | Q3 2025 |
| HTFL | $13.9M | 0.82% | 0.66% | +106.2% | Q3 2025 |
 ARDX | $13.8M | 0.81% | 0.93% | Not reported | Q2 2015 |
 SMMT | $13.5M | 0.79% | 0.09% | Not reported | Q3 2024 |
 AZTA | $12M | 0.71% | 1.23% | Not reported | Q2 2022 |
| MLYS | $11.9M | 0.70% | 0.53% | +2.8% | Q1 2023 |
| DHR | $11.7M | 0.69% | 0.01% | Not reported | Q3 2014 |
| PTCT | $11M | 0.65% | 0.20% | +161.5% | Q1 2015 |
 CAI | $10.1M | 0.59% | 0.20% | -18.1% | Q2 2025 |
| ZBIO | $9.82M | 0.58% | 0.80% | Not reported | Q3 2024 |
| BCAX | $9.73M | 0.57% | 0.75% | +14.0% | Q3 2024 |
 BBIO | $9.52M | 0.56% | 0.07% | +23.9% | Q3 2025 |
| Q4 2025 | |||||
| LLY | $113M | 5.81% | 0.01% | Not reported | Q1 2015 |
| RVMD | $106M | 5.45% | 0.68% | Not reported | Q1 2023 |
| ARGX | $86.8M | 4.45% | 0.17% | -27.7% | Q2 2018 |
| TVTX | $84.5M | 4.33% | 2.43% | +2.1% | Q4 2020 |
| MDGL | $81.3M | 4.17% | 0.61% | +1.4% | Q3 2016 |
| RYTM | $74.4M | 3.81% | 1.03% | -3.1% | Q4 2017 |
 EXK | $61.1M | 3.13% | 0.23% | +1.4% | Q3 2016 |
| MIRM | $60.2M | 3.09% | 1.47% | +0.2% | Q3 2019 |
| INSM | $55.6M | 2.85% | 0.15% | -17.1% | Q1 2015 |
| GPCR | $52M | 2.67% | 0.35% | -21.3% | Q4 2023 |
| ISRG | $46.4M | 2.38% | 0.02% | Not reported | Q4 2013 |
| CDTX | $45.3M | 2.32% | 0.65% | -17.9% | Q2 2015 |
| ASND | $43.4M | 2.23% | 0.33% | -5.1% | Q1 2015 |
| IRTC | $41.7M | 2.14% | 0.73% | Not reported | Q3 2017 |
| KYMR | $38.7M | 1.98% | 0.61% | +10.3% | Q3 2020 |
| BSX | $38M | 1.95% | 0.03% | +10.8% | Q2 2018 |
| PEN | $37.5M | 1.92% | 0.31% | Not reported | Q3 2015 |
| XENE | $35.3M | 1.81% | 0.98% | -7.5% | Q1 2020 |
| SRRK | $32.3M | 1.66% | 0.68% | -7.6% | Q4 2024 |
| COGT | $30.2M | 1.55% | 0.53% | -15.8% | Q2 2025 |
| RARE | $29.1M | 1.49% | 1.31% | +1.7% | Q1 2014 |
| VERA | $28.8M | 1.48% | 0.89% | -7.9% | Q1 2024 |
| ALNY | $28.3M | 1.45% | 0.05% | -4.0% | Q2 2017 |
| FOLD | $27.5M | 1.41% | 0.62% | -0.9% | Q2 2015 |
| THC | $24.8M | 1.27% | 0.14% | Not reported | Q4 2024 |
| DXCM | $23.1M | 1.18% | 0.09% | +9.6% | Q1 2021 |
| AGIO | $21.8M | 1.12% | 1.37% | -16.6% | Q1 2019 |
| TARS | $21.3M | 1.09% | 0.61% | -9.7% | Q4 2024 |
| CMPX | $21.1M | 1.08% | 2.20% | -12.2% | Q4 2021 |
| NAMS | $19.5M | 1.00% | 0.49% | -6.5% | Q3 2024 |
| AZTA | $18.9M | 0.97% | 1.24% | +5.3% | Q2 2022 |
| CLDX | $18.8M | 0.96% | 1.04% | -4.0% | Q1 2022 |
| CAI | $18.5M | 0.95% | 0.24% | -13.4% | Q2 2025 |
| ZBIO | $18.2M | 0.93% | 0.92% | -13.5% | Q3 2024 |
| DYN | $17.9M | 0.92% | 0.55% | +10.8% | Q1 2024 |
| NBIX | $17.8M | 0.91% | 0.13% | +39.8% | Q1 2014 |
| PHVS | $17.3M | 0.89% | 0.96% | Not reported | Q1 2024 |
| MLYS | $15.5M | 0.80% | 0.52% | +4.7% | Q1 2023 |
 PHR | $14.8M | 0.76% | 1.45% | +17.0% | Q3 2019 |
| ZLAB | $14.3M | 0.73% | 0.07% | +2.6% | Q3 2017 |
| DHR | $14.1M | 0.72% | 0.01% | Not reported | Q3 2014 |
| UNH | $13.5M | 0.69% | 0.00% | Not reported | Q4 2013 |
| ARDX | $13.4M | 0.69% | 0.94% | +0.6% | Q2 2015 |
| ACRS | $13.4M | 0.69% | 3.70% | -3.4% | Q4 2015 |
| SMMT | $12.4M | 0.64% | 0.09% | Not reported | Q3 2024 |
| ELVN | $12.3M | 0.63% | 1.34% | +16.4% | Q1 2024 |
 INSP | $12.1M | 0.62% | 0.46% | +18.6% | Q1 2020 |
 OMDA | $11.7M | 0.60% | 1.27% | -19.6% | Q2 2025 |
| SLNO | $11.4M | 0.59% | 0.47% | +59.9% | Q4 2024 |
| ACLX | $11.1M | 0.57% | 0.29% | -5.1% | Q2 2025 |
| Q3 2025 | |||||
| ARGX | $105M | 6.15% | 0.23% | -18.8% | Q2 2018 |
| LLY | $80.4M | 4.70% | 0.01% | -9.5% | Q1 2015 |
| RYTM | $72.4M | 4.23% | 1.08% | -16.7% | Q4 2017 |
| MDGL | $63.2M | 3.69% | 0.61% | -1.8% | Q3 2016 |
| RVMD | $62.4M | 3.64% | 0.70% | +0.3% | Q1 2023 |
| MRUS | $56.2M | 3.28% | 0.79% | -43.9% | Q2 2016 |
| MIRM | $55.8M | 3.26% | 1.48% | -7.0% | Q3 2019 |
| INSM | $55.4M | 3.24% | 0.18% | -26.7% | Q1 2015 |
| TVTX | $51.7M | 3.02% | 2.42% | +13.5% | Q4 2020 |
| ASND | $42.6M | 2.49% | 0.35% | -1.2% | Q1 2015 |
| IRTC | $40.4M | 2.36% | 0.73% | -3.1% | Q3 2017 |
| AGIO | $38.5M | 2.25% | 1.64% | -3.2% | Q1 2019 |
| RARE | $37.5M | 2.19% | 1.29% | -10.4% | Q1 2014 |
| ISRG | $36.7M | 2.14% | 0.02% | Not reported | Q4 2013 |
| BSX | $35.2M | 2.05% | 0.02% | +1.5% | Q2 2018 |
| XENE | $34.2M | 2.00% | 1.10% | -8.6% | Q1 2020 |
| ALNY | $33.9M | 1.98% | 0.06% | -25.8% | Q2 2017 |
| EXK | $32.5M | 1.90% | 0.23% | +3.8% | Q3 2016 |
| PEN | $30.5M | 1.78% | 0.31% | -6.2% | Q3 2015 |
| AKRO | $29.7M | 1.74% | 0.78% | -2.2% | Q2 2019 |
| SRRK | $29.6M | 1.73% | 0.80% | Not reported | Q4 2024 |
| ZLAB | $26.8M | 1.57% | 0.07% | -9.2% | Q3 2017 |
| GPCR | $26.6M | 1.56% | 0.52% | -16.3% | Q4 2023 |
| KYMR | $25.5M | 1.49% | 0.63% | Not reported | Q3 2020 |
| THC | $25.4M | 1.48% | 0.14% | -3.9% | Q4 2024 |
| EVH | $25M | 1.46% | 2.51% | +4.6% | Q1 2021 |
| CAI | $24M | 1.40% | 0.28% | Not reported | Q2 2025 |
| CDTX | $23.9M | 1.40% | 0.85% | +85.9% | Q2 2015 |
| DXCM | $21.3M | 1.25% | 0.08% | +10.5% | Q1 2021 |
| OMDA | $20.3M | 1.19% | 1.59% | 0.0% | Q2 2025 |
| CLDX | $18.7M | 1.09% | 1.09% | -11.2% | Q1 2022 |
| VERA | $17.9M | 1.05% | 0.97% | Not reported | Q1 2024 |
| PHR | $17.6M | 1.03% | 1.25% | -10.5% | Q3 2019 |
| TARS | $17.1M | 1.00% | 0.68% | -22.9% | Q4 2024 |
| NAMS | $16.9M | 0.99% | 0.53% | +11.2% | Q3 2024 |
| CMPX | $15.7M | 0.92% | 2.52% | -9.8% | Q4 2021 |
| PHVS | $15.6M | 0.91% | 1.15% | Not reported | Q1 2024 |
| AZTA | $15.5M | 0.91% | 1.18% | +1.9% | Q2 2022 |
| MLYS | $15.5M | 0.90% | 0.52% | +25.8% | Q1 2023 |
| FOLD | $15.3M | 0.90% | 0.63% | -0.7% | Q2 2015 |
| ACLX | $14.7M | 0.86% | 0.31% | -3.9% | Q2 2025 |
| SMMT | $14.7M | 0.86% | 0.10% | Not reported | Q3 2024 |
| COGT | $14.5M | 0.85% | 0.72% | +26.0% | Q2 2025 |
| ELVN | $14M | 0.82% | 1.16% | -2.2% | Q1 2024 |
| ZBIO | $12.9M | 0.75% | 1.38% | -9.3% | Q3 2024 |
| NBIX | $12.6M | 0.74% | 0.09% | +1.1% | Q1 2014 |
| ARDX | $12.6M | 0.74% | 0.94% | Not reported | Q2 2015 |
| DHR | $12.2M | 0.71% | 0.01% | +4.2% | Q3 2014 |
 LENZ | $11M | 0.64% | 0.83% | +181.3% | Q4 2024 |
| SLNO | $10.4M | 0.61% | 0.29% | Not reported | Q4 2024 |