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Funds (13F)

Rock Springs Capital Management LP

Backtest from 21 Feb 2014 to 2 Nov 2026 · weekly · hypothetical

Watch this strategy
Return a year
+6.4%
S&P 500 +13.7%
Last 12 months
+8.2%
S&P 500 +12.1%
Sharpe ratio
0.30
S&P 500 0.75
Biggest drop
−45.5%
S&P 500 −31.8%
$10.0k$20.0k$40.0k 2014201620182020202220242026 $50.9k$22.0k
StrategyS&P 500 $10,000 in Rock Springs Capital Management LP from 21 Feb 2014 against the S&P 500 (total return) over the same dates, marked weekly, log scale. Hypothetical: before taxes and trading costs.

About

Copies Rock Springs Capital Management LP's quarterly 13F holdings in the companies we cover, weighted by reported value: it buys on the first trading day after each 13F is filed (up to 45 days after the quarter) and holds until the next filing. A 13F shows long US-listed positions only, at the quarter's end, so this misses shorts, cash, bonds, non-US holdings and trading within the quarter.

Rock Springs Capital Management LP's 13F holdings →

Key statistics

MeasureStrategyS&P 500
Return a year (compound)+6.4%+13.7%
Total return+120%+409%
Last 12 months+8.2%+12.1%
Last 3 months−5.4%—
Last month−1.7%—
This year so far−1.5%—
Volatility a year23.0%16.2%
Sharpe ratio0.300.75
Biggest drop−45.5%−31.8%
Beta to the S&P 5001.031.00
Alpha a year (t-statistic)−5.7% (−1.27)—
Share of weeks up52%—

Sharpe ratio uses returns above the 3-month Treasury bill rate. Alpha is the yearly return left after allowing for the strategy's exposure to the S&P 500 (CAPM); a t-statistic below about 2 means it cannot be told apart from luck.

Insights

CompanyWeightHeld sinceReturn since
RVMD10.1%——
TVTX6.1%——
LLY5.8%——
MDGL4.6%——
MIRM4.6%——
RYTM3.8%——
KYMR2.5%——
ARGX2.4%——
ASND2.2%——
XENE2.0%——
SRRK1.9%——
INSM1.9%——
PEN1.8%——
GPCR1.7%——
RARE1.6%——
IRTC1.6%——
ISRG1.5%——
AGL1.4%——
UNH1.3%——
CLDX1.3%——
ERAS1.3%——
NBIX1.2%——
ELVN1.1%——
THC1.1%——
DXCM1.1%——
ACRS1.1%——
MMED1.1%——
BSX1.1%——
PHVS1.1%——
AVLN1.1%——
COAG1.0%——
DYN1.0%——
ALNY1.0%——
COGT1.0%——
AGIO1.0%——
NAMS1.0%——
VERA0.9%——
TARS0.8%——
HTFL0.8%——
MBX0.8%——
CYTK0.8%——
BCAX0.8%——
PBLS0.8%——
ZLAB0.8%——
DHR0.7%——
TNGX0.7%——
EVH0.7%——
PTCT0.7%——
MLYS0.6%——
ZBIO0.6%——
ARDX0.6%——
INSP0.5%——
BBIO0.5%——
ALKS0.5%——
SMMT0.5%——
AZTA0.5%——
INDV0.5%——
SYK0.5%——
AMLX0.4%——
CAI0.4%——
OMDA0.4%——
CMPX0.4%——
IMNM0.4%——
FOCL0.3%——
OMER0.3%——
DFTX0.3%——
CORT0.3%——
JANX0.3%——
MOBI0.3%——
RCUS0.3%——
TMO0.3%——
TRVI0.2%——
SION0.2%——
CVS0.2%——
EYPT0.2%——
OCUL0.2%——
SYRE0.2%——
TLPH0.2%——
ROIV0.2%——
PCVX0.2%——
NGNE0.2%——
IPSC0.2%——
ATEC0.1%——
NVO0.1%——
OLMA0.1%——
NGEN0.1%——
MDT0.1%——
TEVA0.1%——
DNTH0.1%——
SGMT0.1%——
CAPR0.1%——
LENZ0.1%——
ALT0.1%——
KLRA0.1%——
SGRY0.1%——
AXSM0.1%——
ORKA0.1%——
VKTX0.1%——
LEGN0.1%——
GKOS0.0%——
JSPR0.0%——
BCRX0.0%——
MLTX0.0%——

Weighted by reported value in the latest 13F, held until the next filing.

PeriodReturn a yearS&P 500SharpeS&P 500Biggest dropBetaAlpha (t)
Whole backtest21 Feb 2014 to 2 Nov 2026+6.4%+13.7%0.300.75−45.5%1.03−5.7% (−1.27)
2018 onwards5 Jan 2018 to 2 Nov 2026+5.0%+13.9%0.210.66−45.5%1.02−6.9% (−1.25)
Last three years3 Nov 2023 to 2 Nov 2026+12.5%+21.8%0.441.16−25.7%0.92−5.2% (−0.51)
Last year7 Nov 2025 to 2 Nov 2026+11.1%+14.2%0.390.84−17.9%1.00−0.5% (−0.02)
DateCompanyAction
21 Aug 2026TRVIBought
21 Aug 2026SYREBought
21 Aug 2026SGMTBought
21 Aug 2026PBLSBought
21 Aug 2026OMERBought
21 Aug 2026NGENBought
21 Aug 2026MOBIBought
21 Aug 2026MDTBought
21 Aug 2026KLRABought
21 Aug 2026GKOSBought
21 Aug 2026DFTXBought
21 Aug 2026COAGBought
21 Aug 2026CAPRBought
21 Aug 2026AXSMBought
21 Aug 2026AVLNBought
21 Aug 2026ASNDBought
21 Aug 2026ALTBought
22 May 2026VKTXBought
22 May 2026SYKBought
22 May 2026ORKABought
22 May 2026NVOBought
22 May 2026MMEDBought
22 May 2026IPSCBought
22 May 2026INDVBought
22 May 2026DNTHBought

Dated at the rebalance that made the change.

DateCompanyAction
21 Aug 2026REGNSold
21 Aug 2026JAZZSold
21 Aug 2026GOSSSold
21 Aug 2026EWSold
21 Aug 2026ACHCSold
20 Feb 2026WSTSold
20 Feb 2026PRTASold
20 Feb 2026NVAXSold
20 Feb 2026MREOSold
20 Feb 2026KRROSold
20 Feb 2026IMVTSold
20 Feb 2026CRLSold
20 Feb 2026CGENSold
20 Feb 2026CATXSold
21 Nov 2025UNHSold
21 Nov 2025SRPTSold
21 Nov 2025OSCRSold
21 Nov 2025LUNGSold
21 Nov 2025CGEMSold
15 Aug 2025WRBYSold
15 Aug 2025SGMTSold
15 Aug 2025PLRXSold
15 Aug 2025MGNXSold
15 Aug 2025LEGNSold
15 Aug 2025KMTSSold

Dated at the rebalance that made the change.

Backtests are hypothetical and use today's listed companies only, which flatters results. Past performance does not predict future returns. This is research, not investment advice. How we backtest