InterContinental Hotels Group PLC ADR (IHG) had the highest return between 2003 and 2012 by a large-cap US stock, returning 20,601,300%.

ASSET	YEARS	% RETURN
InterContinental Hotels Group PLC ADR (IHG)	2003-2012	20,601,300%
National Grid PLC ADR (NGG)	2003-2012	1,746,456.25%
Ferguson (FERG)	2003-2012	996,060.61%
Natwest (NWG)	2003-2012	678,100%
QXO (QXO)	2003-2012	115,105%
Monster Beverage (MNST)	2003-2012	19,960.82%
Apple (AAPL)	2003-2012	7,375.74%
Booking (BKNG)	2003-2012	6,282.62%
Banco Bradesco SA ADR (BBD)	2003-2012	4,870.87%
Ambev SA ADR (ABEV)	2003-2012	4,572.35%
Grupo Cibest (CIB)	2003-2012	4,018.93%
Intuitive Surgical (ISRG)	2003-2012	3,886.94%
Deckers Outdoor (DECK)	2003-2012	3,549.65%
Williams Companies (WMB)	2003-2012	3,232.05%
Illumina (ILMN)	2003-2012	3,160.33%
Southern Copper (SCCO)	2003-2012	3,056.78%
Cheniere Energy (LNG)	2003-2012	2,789.19%
Sociedad Quimica y Minera de Chile SA ADR B (SQM)	2003-2012	2,584.36%
Axon Enterprise (AXON)	2003-2012	2,548.89%
Companhia de Saneamento Basico do Estado de Sao Paulo SABESP ADR (SBS)	2003-2012	2,353.35%
Alamos Gold (AGI)	2003-2012	2,207.16%
Akamai Technologies (AKAM)	2003-2012	2,172.78%
Chunghwa Telecom (CHT)	2003-2012	2,016.77%
Credicorp (BAP)	2003-2012	1,962.22%
Cummins (CMI)	2003-2012	1,719.83%

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