AerCap (AER) had the best month in January 2009 by a large-cap US stock in January 2009, returning 54.1%.

ASSET	MONTH	% RETURN
AerCap (AER)	January 2009	54.12%
Hudbay Minerals (HBM)	January 2009	50.01%
Cheniere Energy Partners (CQP)	January 2009	42.83%
Domino's Pizza Inc Common Stock (DPZ)	January 2009	41.73%
Micron Technology (MU)	January 2009	40.38%
Madrigal Pharmaceuticals (MDGL)	January 2009	39.24%
Synnex (SNX)	January 2009	34.41%
Morgan Stanley (MS)	January 2009	28.11%
HF Sinclair (DINO)	January 2009	27.91%
Western Digital (WDC)	January 2009	26.55%
Cheniere Energy (LNG)	January 2009	23.95%
TechnipFMC (FTI)	January 2009	23.34%
Netflix (NFLX)	January 2009	22.43%
ON Semiconductor (ON)	January 2009	21.57%
Tower Semiconductor (TSEM)	January 2009	21.43%
Globalstar, Inc Common Stock (GSAT)	January 2009	20%
Woori Financial (WF)	January 2009	19.26%
Check Point Software Technologies (CHKP)	January 2009	18.88%
Franco-Nevada (FNV)	January 2009	17.92%
DexCom (DXCM)	January 2009	17.03%
Brookfield Infrastructure Partners (BIP)	January 2009	16.81%
Agilent Technologies (A)	January 2009	15.9%
TTM Technologies (TTMI)	January 2009	15.74%
Vale SA ADR (VALE)	January 2009	15.47%
CMS Energy (CMS)	January 2009	15.42%

Large-cap stocks are treated as having a market cap of $10B+.