Rock Springs Capital Management LP
Long book
$1.70B
Q1 2026
Positions
100
Top-10 weight
41%
concentration
Last quarter
+24.9%
SPY +14.8%
Turnover
18%
of book per quarter
Strategy in plain words
auto-generated from filingsRock Springs Capital Management LP is a diversified fundamental manager, specialised in healthcare (95% of the long book), running a $1.70B US long book across 100 positions.
The portfolio is moderately concentrated (top 10 ≈ 41% of the book). Turnover is modest: positions are typically held for years. Current anchor positions: REVOLUTION MEDICINES INC, ELI LILLY & CO, MADRIGAL PHARMACEUTICALS INC, MIRUM PHARMACEUTICALS INC, ARGENX SE - ADR.
Over the last 9 quarters its long book ran on average 0.5pp per quarter ahead of the S&P 500, beating the index in 4 of 9 quarters. We rate its filings as signal-bearing: position changes reflect genuine views.
Implied long-book return vs S&P 500
methodology: positions priced quarterly, no shorts/options Fund long book S&P 500
Q1 2024
-5.6%
Q2 2024
+6.6%
Q3 2024
-4.4%
Q4 2024
-9.6%
Q1 2025
+3.6%
Q2 2025
+19.3%
Q3 2025
+16.8%
Q4 2025
-6.3%
Q1 2026
+24.9%
Sector allocation
Healthcare 92%
Other 3%
Materials 1%
Financials 1%
Industrials 1%
Technology 1%
Services media 1%
Long book by quarter
What does Rock Springs own?
Q1 2026 13F| Company | Sector | Shares | Value | % of book | Change |
|---|---|---|---|---|---|
| RVMD REVOLUTION MEDICINES INC | Healthcare | 1.2M | $117.6M | 6.9% | -9.4% |
| LLY ELI LILLY & CO | Healthcare | 98.7K | $90.8M | 5.4% | -6.4% |
| MDGL MADRIGAL PHARMACEUTICALS INC | Healthcare | 171.0K | $89.5M | 5.3% | +22.5% |
| MIRM MIRUM PHARMACEUTICALS INC | Healthcare | 811.3K | $74.9M | 4.4% | +6.4% |
| RYTM RHYTHM PHARMACEUTICALS INC | Healthcare | 689.7K | $60.0M | 3.5% | -0.8% |
| INSM INSMED INC | Healthcare | 314.3K | $51.4M | 3.0% | -1.6% |
| XENE XENON PHARMACEUTICALS INC | Healthcare | 763.0K | $44.4M | 2.6% | -3.1% |
| TVTX TRAVERE THERAPEUTICS INC | Healthcare | 1.5M | $43.9M | 2.6% | -33.1% |
| KYMR KYMERA THERAPEUTICS INC | Healthcare | 496.9K | $41.4M | 2.4% | Held |
| PEN PENUMBRA INC | Healthcare | 120.5K | $39.6M | 2.3% | Held |
| ISRG INTUITIVE SURGICAL INC | Healthcare | 82.0K | $37.8M | 2.2% | Held |
| SRRK SCHOLAR ROCK HOLDING CORP | Healthcare | 739.8K | $36.4M | 2.1% | +0.9% |
| ELVN ENLIVEN THERAPEUTICS INC | Healthcare | 826.5K | $32.4M | 1.9% | +3.5% |
| BSX BOSTON SCIENTIFIC CORP | Healthcare | 515.3K | $32.3M | 1.9% | +29.1% |
| IRTC IRHYTHM HOLDINGS INC | Healthcare | 261.8K | $30.9M | 1.8% | +11.4% |
| AGIO AGIOS PHARMACEUTICALS INC | Healthcare | 799.2K | $27.0M | 1.6% | Held |
| RARE ULTRAGENYX PHARMACEUTICAL IN | Healthcare | 1.2M | $25.5M | 1.5% | -3.8% |
| ALNY ALNYLAM PHARMACEUTICALS INC | Healthcare | 74.0K | $24.5M | 1.4% | +3.9% |
| COGT COGENT BIOSCIENCES INC | Healthcare | 624.2K | $24.0M | 1.4% | -26.5% |
| THC TENET HEALTHCARE CORP | Healthcare | 125.0K | $23.6M | 1.4% | Held |
| DXCM DEXCOM INC | Healthcare | 355.6K | $22.3M | 1.3% | +2.4% |
| CLDX CELLDEX THERAPEUTICS INC | Materials | 650.3K | $20.6M | 1.2% | -6.1% |
| VERA VERA THERAPEUTICS INC | Healthcare | 503.6K | $20.3M | 1.2% | -11.4% |
| NBIX NEUROCRINE BIOSCIENCES INC | Healthcare | 150.4K | $19.8M | 1.2% | +19.9% |
| ACLXGBX ARCELLX INC | — | 169.9K | $19.5M | 1.1% | Held |
| NAMS NEWAMSTERDAM PHARMA CO NV | Healthcare | 588.8K | $18.8M | 1.1% | +5.7% |
| PHVS PHARVARIS NV | Healthcare | 645.5K | $18.2M | 1.1% | +3.6% |
| ERAS ERASCA INC | Healthcare | 1.1M | $17.9M | 1.1% | +15.9% |
| DYN DYNE THERAPEUTICS INC | Healthcare | 972.2K | $17.6M | 1.0% | +6.5% |
| CMPX COMPASS THERAPEUTICS INC | Healthcare | 3.3M | $17.5M | 1.0% | -15.8% |
| ACRS ACLARIS THERAPEUTICS INC | Healthcare | 4.5M | $16.8M | 1.0% | +0.4% |
| TARS TARSUS PHARMACEUTICALS INC | Healthcare | 225.2K | $15.8M | 0.9% | -13.5% |
| MMED MINIMED GROUP INC | Healthcare | 1.1M | $15.7M | 0.9% | New |
| UNH UNITEDHEALTH GROUP INC | Financials | 53.0K | $14.3M | 0.8% | +29.9% |
| HTFL HEARTFLOW INC | Healthcare | 572.5K | $13.9M | 0.8% | +106.2% |
| ARDX ARDELYX INC | Healthcare | 2.3M | $13.8M | 0.8% | Held |
| SMMT SUMMIT THERAPEUTICS INC | Healthcare | 710.0K | $13.5M | 0.8% | Held |
| AZTA AZENTA INC | Industrials | 569.1K | $12.0M | 0.7% | Held |
| MLYS MINERALYS THERAPEUTICS INC | Healthcare | 439.8K | $11.9M | 0.7% | +2.8% |
| DHR DANAHER CORP | Technology | 61.5K | $11.7M | 0.7% | Held |
| PTCT PTC THERAPEUTICS INC | Healthcare | 161.8K | $11.0M | 0.6% | +161.5% |
| CAI CARIS LIFE SCIENCES INC | Healthcare | 563.0K | $10.1M | 0.6% | -18.1% |
| ZBIO ZENAS BIOPHARMA INC | Healthcare | 502.1K | $9.8M | 0.6% | Held |
| BCAX BICARA THERAPEUTICS INC | Healthcare | 489.1K | $9.7M | 0.6% | +14.0% |
| BBIO BRIDGEBIO PHARMA INC | Healthcare | 128.3K | $9.5M | 0.6% | +23.9% |
| SLNOEUR SOLENO THERAPEUTICS INC | — | 257.3K | $8.6M | 0.5% | +4.1% |
| MBX MBX BIOSCIENCES INC | Healthcare | 288.0K | $8.6M | 0.5% | +1.9% |
| TNGX TANGO THERAPEUTICS INC | Healthcare | 386.9K | $8.1M | 0.5% | Held |
| REGN REGENERON PHARMACEUTICALS | Healthcare | 10.1K | $7.8M | 0.5% | Held |
| IMNM IMMUNOME INC | Healthcare | 347.7K | $7.6M | 0.4% | Held |
13F filing history
| Period | Form | Filed | Entries | Reported value | Flags | Source |
|---|---|---|---|---|---|---|
| Q1 2026 | 13F-HR | May 15, 2026 | 100 | $1.70B | canonical | SEC ↗ |
| Q4 2025 | 13F-HR | Feb 17, 2026 | 99 | $1.95B | canonical | SEC ↗ |
| Q3 2025 | 13F-HR | Nov 14, 2025 | 93 | $1.71B | canonical | SEC ↗ |
| Q2 2025 | 13F-HR | Aug 14, 2025 | 93 | $1.60B | canonical | SEC ↗ |
| Q1 2025 | 13F-HR | May 15, 2025 | 96 | $1.75B | canonical | SEC ↗ |
| Q4 2024 | 13F-HR | Feb 14, 2025 | 107 | $2.63B | canonical | SEC ↗ |
| Q3 2024 | 13F-HR | Nov 14, 2024 | 109 | $3.07B | canonical | SEC ↗ |
| Q2 2024 | 13F-HR | Aug 14, 2024 | 112 | $3.32B | canonical | SEC ↗ |
| Q1 2024 | 13F-HR | May 15, 2024 | 114 | $3.94B | canonical | SEC ↗ |