InterContinental Hotels Group PLC ADR (IHG) had the highest return between 2003 and 2006 by a large-cap US stock, returning 16,461,200%.

ASSET	YEARS	% RETURN
InterContinental Hotels Group PLC ADR (IHG)	2003-2006	16,461,200%
National Grid PLC ADR (NGG)	2003-2006	1,428,843.75%
Monster Beverage (MNST)	2003-2006	6,293.39%
Cheniere Energy (LNG)	2003-2006	4,341.49%
Akamai Technologies (AKAM)	2003-2006	2,851.11%
Axon Enterprise (AXON)	2003-2006	2,154.81%
ArcelorMittal SA ADR (MT)	2003-2006	2,015.34%
Williams Companies (WMB)	2003-2006	1,769.17%
Deckers Outdoor (DECK)	2003-2006	1,711.09%
Grupo Cibest (CIB)	2003-2006	1,496.32%
Allegheny Technologies (ATI)	2003-2006	1,493.67%
Banco Bradesco SA ADR (BBD)	2003-2006	1,447.36%
Tenaris SA ADR (TS)	2003-2006	1,365.42%
Sterling Construction (STRL)	2003-2006	1,143.43%
CME (CME)	2003-2006	1,104.16%
Apple (AAPL)	2003-2006	1,081.31%
Illumina (ILMN)	2003-2006	1,052.76%
Teck Resources Ltd Class B (TECK)	2003-2006	998.9%
Alamos Gold (AGI)	2003-2006	968.01%
WESCO International (WCC)	2003-2006	952.07%
Cameco (CCJ)	2003-2006	937.43%
Chunghwa Telecom (CHT)	2003-2006	922.26%
Southern Copper (SCCO)	2003-2006	912.68%
Vale SA ADR (VALE)	2003-2006	894.38%
America Movil SAB de CV ADR (AMX)	2003-2006	877.72%

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