Stocks/Funds/CIK 1595725

Rock Springs Capital Management LP

long-term holder
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1595725
Assets
$1.65B
-3.4% YoY
Holdings
99
Lifetime alpha vs market
-7.48% annual
Average hold time
3.5 yr
median 2.3 yr

Quarterly history

Cum return +12% vs S&P +52% · α -41% lifetimeAUM $1.6B · peak $5.0BFlow $-121M (-6%)2016-062017-122019-062020-122022-062023-122025-062026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
-6.40%
trims when stocks drop
when a holding falls −10%+
Middle response
-5.30%
baseline attrition
Rally response
-5.69%
trims into rallies
when a holding rises +10%+

Top positions · 30

Ticker$ value% portYoYHold time
RVMDRevolution Medicines, In$118M7.1%+175.0%3.3 yr
LLYEli Lilly and Company$91M5.5%+12.2%4.0 yr
MDGLMadrigal Pharmaceuticals$90M5.4%+58.0%9.8 yr
MIRMMirum Pharmaceuticals, I$75M4.6%+105.1%6.8 yr
ARGXargenx SE$72M4.4%+23.4%8.0 yr
RYTMRhythm Pharmaceuticals, $60M3.6%+64.2%8.5 yr
$44M2.7%10.5 yr
XENEXenon Pharmaceuticals In$44M2.7%+73.3%6.3 yr
TVTXTravere Therapeutics, In$44M2.7%+65.8%5.5 yr
KYMRKymera Therapeutics, Inc$41M2.5%+204.3%5.8 yr
PENPenumbra, Inc.$40M2.4%+22.8%10.5 yr
ISRGIntuitive Surgical, Inc.$38M2.3%-6.9%10.5 yr
SRRKScholar Rock Holding Cor$36M2.2%+52.9%1.5 yr
ELVNEnliven Therapeutics, In$32M2.0%+99.2%2.3 yr
BSXBoston Scientific Corpor$32M2.0%-37.8%6.3 yr

Portfolio composition (YoY)

Industry mix
Biotechnology70.4%+8.8pp$1.16B
Medical - Devices11.3%-2.0pp$186M
Drug Manufacturers - General5.5%+0.0pp$91M
Unknown4.4%-0.7pp$73M
Medical - Care Facilities2.8%+0.5pp$46M
Medical - Healthcare Information Services1.9%-1.3pp$32M
Medical - Healthcare Plans1.0%-2.9pp$17M
Medical - Diagnostics & Research1.0%-0.9pp$17M
Semiconductors0.7%-0.2pp$12M
Drug Manufacturers - Specialty & Generic0.6%+0.6pp$10M
Country
US84.3%+3.9pp
NL5.5%-3.6pp
Unknown4.4%-0.7pp
CA2.7%+0.9pp
GB1.0%+0.1pp
CN0.9%-1.0pp
IE0.5%+0.1pp
FR0.3%+0.2pp
Top 5: 27.0% · Top 10: 41.3% · Top 25: 67.3%

Winners

TickerPrev $PnLYoY %
RVMD$45M+0.08B175.0%
MIRM$43M+0.05B105.1%
KYMR$22M+0.04B204.3%
GPCR$20M+0.03B178.5%
TVTX$52M+0.03B65.8%

Losers

TickerPrev $PnLYoY %
RARE$50M-0.02B-42.1%
BSX$28M-0.01B-37.8%
ISRG$51M-0.00B-6.9%
DXCM$27M-0.00B-8.0%

Top buys this quarter · 15

MDGL Madrigal Pharmaceuticals, Inc.+$16M
BSX Boston Scientific Corporation+$32M
HTFL Heartflow, Inc. Common Stock+$7M
PTCT PTC Therapeutics, Inc.+$7M
INDV Indivior Pharmaceuticals Incnew+$6M
MIRM Mirum Pharmaceuticals, Inc.+$5M
UNH UnitedHealth Group Incorporate+$3M
NBIX Neurocrine Biosciences, Inc.+$3M
IRTC iRhythm Technologies, Inc.+$31M
IPSC Century Therapeutics, Inc.new+$3M

Top sells this quarter · 15

EXAS Exact Sciences Corporationexit$63M
SYK Stryker Corporation$54M
FOLD Amicus Therapeutics, Inc.$28M
TVTX Travere Therapeutics, Inc.$22M
RVMD Revolution Medicines, Inc.$106M
COGT Cogent Biosciences, Inc.$9M
LLY Eli Lilly and Company$6M
VKTX Viking Therapeutics, Inc.$5M
GPCR Structure Therapeutics Inc.$5M
EW Edwards Lifesciences Corporati$4M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$1.65B99+31.78%+17.59%+14.19%-0.12B
2025-12-31$1.89B96+28.83%+17.72%+11.11%-0.04B
2025-09-30$1.65B90+5.62%+17.52%-11.89%-0.17B
2025-06-30$1.55B91-2.92%+14.94%-17.87%-0.20B
2025-03-31$1.70B94-11.77%+8.30%-20.07%-0.66B
2024-12-31$2.58B104-2.06%+24.89%-26.95%-0.31B
2024-09-30$3.02B106+12.42%+36.04%-23.62%-0.49B
2024-06-30$3.25B106-7.53%+24.49%-32.02%-0.40B
2024-03-31$3.93B109+3.23%+29.62%-26.39%-0.18B
2023-12-31$4.04B99+0.39%+26.18%-25.78%-0.06B
2023-09-30$3.72B116-1.36%+21.57%-22.93%-0.00B
2023-06-30$4.20B119+17.53%+19.42%-1.89%-0.15B
2023-03-31$4.18B116-7.10%-7.82%+0.71%+0.08B
2022-12-31$4.15B116+8.27%+7.56%+0.71%-0.03B
2022-09-30$3.86B122+5.80%-4.93%+10.73%+0.24B
2022-06-30$3.42B125-17.89%-16.11%-1.78%+0.20B