National Grid PLC ADR (NGG) had the highest return between 2003 and 2007 by a large-cap US stock, returning 1,704,843.8%.

ASSET	YEARS	% RETURN
National Grid PLC ADR (NGG)	2003-2007	1,704,843.75%
Monster Beverage (MNST)	2003-2007	8,307.29%
Cheniere Energy (LNG)	2003-2007	4,921.47%
Deckers Outdoor (DECK)	2003-2007	4,584.28%
Axon Enterprise (AXON)	2003-2007	4,163.7%
Banco Bradesco SA ADR (BBD)	2003-2007	3,871.89%
ArcelorMittal SA ADR (MT)	2003-2007	3,840.47%
Apple (AAPL)	2003-2007	2,658.07%
Intuitive Surgical (ISRG)	2003-2007	2,526.15%
Williams Companies (WMB)	2003-2007	2,493.52%
Vale SA ADR (VALE)	2003-2007	2,112.67%
Southern Copper (SCCO)	2003-2007	2,026.03%
Petroleo Brasileiro Petrobras SA ADR (PBR)	2003-2007	1,997.48%
Petróleo Brasileiro SA - Petrobras (PBR.A)	2003-2007	1,944.98%
Akamai Technologies (AKAM)	2003-2007	1,822.22%
Bancolombia SA ADR (CIB)	2003-2007	1,704.7%
Illumina (ILMN)	2003-2007	1,637.79%
CME (CME)	2003-2007	1,530.01%
Allegheny Technologies (ATI)	2003-2007	1,427.08%
America Movil SAB de CV ADR (AMX)	2003-2007	1,273.93%
Tenaris SA ADR (TS)	2003-2007	1,237.45%
Itau Unibanco Banco (ITUB)	2003-2007	1,201.53%
Carpenter Technology (CRS)	2003-2007	1,166.59%
Ambev SA ADR (ABEV)	2003-2007	1,129.49%
Booking (BKNG)	2003-2007	1,081.68%

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