NXP Semiconductors (NXPI) had the best month in December 2010 by a large-cap US stock in December 2010, returning 64.3%.

ASSET	MONTH	% RETURN
NXP Semiconductors (NXPI)	December 2010	64.29%
Tenet Healthcare (THC)	December 2010	61.2%
Exelixis (EXEL)	December 2010	39.15%
American International (AIG)	December 2010	37.98%
Ciena (CIEN)	December 2010	36.42%
James Hardie Industries PLC ADR (JHX)	December 2010	33.9%
Jabil Circuit (JBL)	December 2010	30.12%
YPF Sociedad Anonima (YPF)	December 2010	28.59%
Regions Financial (RF)	December 2010	28.41%
Lululemon Athletica (LULU)	December 2010	26.28%
Lennar (LEN.B)	December 2010	25.26%
Companhia de Saneamento Basico do Estado de Sao Paulo SABESP ADR (SBS)	December 2010	25.04%
Shinhan Financial (SHG)	December 2010	24.61%
Corpay (CPAY)	December 2010	23.68%
First Horizon National (FHN)	December 2010	22.76%
Teck Resources Ltd Class B (TECK)	December 2010	22.71%
Builders FirstSource (BLDR)	December 2010	21.6%
Fifth Third Bancorp (FITB)	December 2010	21.2%
Lennar (LEN)	December 2010	21.05%
Manulife Financial (MFC)	December 2010	20.99%
Edwards Lifesciences (EW)	December 2010	20.93%
ON Semiconductor (ON)	December 2010	19.76%
Bank of America (BAC)	December 2010	19.43%
DexCom (DXCM)	December 2010	18.49%
MGM Resorts International (MGM)	December 2010	18.42%

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