InterContinental Hotels Group PLC ADR (IHG) had the highest return between 1999 and 2003 by a large-cap US stock, returning 5,813,300%.

ASSET	YEARS	% RETURN
InterContinental Hotels Group PLC ADR (IHG)	1999-2003	5,813,300%
Thomson Reuters Corporation Common Shares (TRI)	1999-2003	30,662.13%
Insmed (INSM)	1999-2003	1,627.25%
Laboratory Corporation of America (LH)	1999-2003	975.03%
NVR (NVR)	1999-2003	877.2%
Deckers Outdoor (DECK)	1999-2003	864.35%
Hudbay Minerals (HBM)	1999-2003	825.04%
Cognizant Technology Solutions Corp Class A (CTSH)	1999-2003	794.24%
Qualcomm (QCOM)	1999-2003	728.03%
Quest Diagnostics (DGX)	1999-2003	723.8%
Neurocrine Biosciences (NBIX)	1999-2003	679.14%
Tapestry (TPR)	1999-2003	655.01%
Logitech International (LOGI)	1999-2003	608.82%
Coherent (COHR)	1999-2003	545%
Genesis Healthcare (GEN)	1999-2003	541.81%
Tractor Supply (TSCO)	1999-2003	536.5%
Royal Gold (RGLD)	1999-2003	502.66%
East West Bancorp (EWBC)	1999-2003	482.69%
CACI International (CACI)	1999-2003	478.38%
Southern Copper (SCCO)	1999-2003	473.73%
Gilead Sciences (GILD)	1999-2003	468.61%
Teva Pharma Industries Ltd ADR (TEVA)	1999-2003	460.05%
Infosys Ltd ADR (INFY)	1999-2003	455.21%
Clean Harbors (CLH)	1999-2003	448.31%
Lam Research (LRCX)	1999-2003	434.59%

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