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Funds (13F)

RA Capital Management, L.P.

Backtest from 16 Aug 2013 to 2 Nov 2026 · weekly · hypothetical

Watch this strategy
Return a year
−1.7%
S&P 500 +14.1%
Last 12 months
+1.4%
S&P 500 +12.1%
Sharpe ratio
0.13
S&P 500 0.78
Biggest drop
−80.2%
S&P 500 −31.8%
$5.0k$10.0k$20.0k$40.0k 2013201520172019202120232025 $57.0k$7.9k
RA Capital Management, L.P.S&P 500 $10,000 in RA Capital Management, L.P. from 16 Aug 2013 against the S&P 500 (total return) over the same dates, marked weekly, log scale. Hypothetical: before taxes and trading costs.

About

Copies RA Capital Management, L.P.'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.

RA Capital Management, L.P.'s 13F holdings →

Key statistics

MeasureStrategyS&P 500
Return a year (compound)−1.7%+14.1%
Total return−21%+470%
Last 12 months+1.4%+12.1%
Last 3 months−14.3%—
Last month−1.9%—
This year so far−7.6%—
Volatility a year42.2%16.0%
Sharpe ratio0.130.78
Biggest drop−80.2%−31.8%
Beta to the S&P 5001.101.00
Alpha a year (t-statistic)−8.4% (−0.79)—
Share of weeks up50%—

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
ASND24.7%——
PBLS7.1%——
RYTM6.7%——
PCVX6.0%——
SION3.9%——
TYRA3.5%——
EWTX3.1%——
NAMS2.9%——
COAG2.6%——
SEPN2.1%——
BCAX1.9%——
MLYS1.9%——
GHRS1.9%——
IRON1.6%——
SGP1.6%——
ARTV1.6%——
JANX1.6%——
TSHA1.4%——
BCRX1.4%——
ABVX1.4%——
ORKA1.3%——
CLYM1.3%——
SLDB1.1%——
ZLAB1.0%——
SPRY0.8%——
XNCR0.8%——
JBIO0.7%——
NTLA0.7%——
LBRX0.7%——
DFTX0.6%——
ACRS0.6%——
FDMT0.6%——
SANA0.6%——
MNPR0.6%——
ABOS0.5%——
GERN0.5%——
RZLT0.4%——
EVMN0.4%——
VOR0.4%——
IPSC0.4%——
AKTS0.4%——
BIOA0.4%——
CCCC0.3%——
MIRM0.3%——
CAPR0.3%——
PEPG0.3%——
PRLD0.3%——
NKTX0.3%——
QTTB0.3%——
AVR0.3%——
EDIT0.3%——
OVID0.3%——
ASMB0.3%——
ALXO0.2%——
BNTC0.2%——
LENZ0.2%——
LXEO0.2%——
ACRV0.2%——
ALT0.2%——
KPTI0.2%——
DRUG0.2%——
AVTX0.2%——
OKUR0.2%——
FTH0.2%——
AURA0.2%——
SABS0.1%——
SPTX0.1%——
PALI0.1%——
WAY0.1%——
EQ0.1%——
MGNX0.1%——
ACET0.1%——
CRVS0.1%——
RANI0.1%——
HOWL0.0%——
PTN0.0%——

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

PeriodReturn a yearS&P 500SharpeS&P 500Biggest dropBetaAlpha (t)
Whole backtest16 Aug 2013 to 2 Nov 2026−1.7%+14.1%0.130.78−80.2%1.10−8.4% (−0.79)
2018 onwards5 Jan 2018 to 2 Nov 2026−6.0%+13.9%−0.010.66−78.2%1.04−12.9% (−1.06)
Last three years3 Nov 2023 to 2 Nov 2026+13.2%+21.8%0.401.16−54.3%1.41−7.1% (−0.36)
Last year7 Nov 2025 to 2 Nov 2026+11.4%+14.2%0.370.84−25.4%1.22+0.8% (0.02)
DateCompanyAction
21 Aug 2026SPTXBought
21 Aug 2026SANABought
21 Aug 2026QTTBBought
21 Aug 2026PRLDBought
21 Aug 2026PBLSBought
21 Aug 2026ORKABought
21 Aug 2026NTLABought
21 Aug 2026FTHBought
21 Aug 2026EDITBought
21 Aug 2026DFTXBought
21 Aug 2026COAGBought
21 Aug 2026AURABought
21 Aug 2026ASNDBought
21 Aug 2026ALTBought
21 Aug 2026ABVXBought
22 May 2026ZLABBought
22 May 2026XNCRBought
22 May 2026TVTXBought
22 May 2026STROBought
22 May 2026SRPTBought
22 May 2026SGPBought
22 May 2026RNABought
22 May 2026RLMDBought
22 May 2026OKURBought
22 May 2026MPLTBought

Dated at the rebalance that made the change.

DateCompanyAction
21 Aug 2026WGSSold
21 Aug 2026TVTXSold
21 Aug 2026SYRESold
21 Aug 2026STROSold
21 Aug 2026SRPTSold
21 Aug 2026RNASold
21 Aug 2026RLMDSold
21 Aug 2026PRAXSold
21 Aug 2026OLMASold
21 Aug 2026MPLTSold
21 Aug 2026INSPSold
21 Aug 2026HNGESold
21 Aug 2026GRALSold
21 Aug 2026FULCSold
21 Aug 2026DSGNSold
21 Aug 2026DNTHSold
21 Aug 2026CTNMSold
22 May 2026PGNYSold
22 May 2026MDLNSold
22 May 2026KIDSSold
22 May 2026IVVDSold
22 May 2026HCATSold
22 May 2026BLTESold
20 Feb 2026TVTXSold
20 Feb 2026TNGXSold

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