Centene (CNC) had the lowest return in July 2006 by a US stock in the S&P 500 (GSPC), returning -30.6%.

ASSET	MONTH	% RETURN
Centene (CNC)	July 2006	-30.56%
Amazon (AMZN)	July 2006	-30.19%
Westinghouse Air Brake Technologies (WAB)	July 2006	-28.85%
CoStar (CSGP)	July 2006	-27%
Netflix (NFLX)	July 2006	-24.38%
VeriSign (VRSN)	July 2006	-22.35%
Advanced Micro Devices (AMD)	July 2006	-20.79%
Monolithic Power Systems (MPWR)	July 2006	-20.7%
Las Vegas Sands (LVS)	July 2006	-20.32%
Corning (GLW)	July 2006	-19.71%
Expeditors International of Washington (EXPD)	July 2006	-19.64%
Norfolk Southern (NSC)	July 2006	-19.4%
Skyworks Solutions (SWKS)	July 2006	-19.3%
Intuitive Surgical (ISRG)	July 2006	-18.42%
eBay (EBAY)	July 2006	-18.27%
JB Hunt Transport Services (JBHT)	July 2006	-17.63%
WW Grainger (GWW)	July 2006	-17.59%
Trane Technologies (TT)	July 2006	-17.38%
Best Buy (BBY)	July 2006	-17.17%
United Parcel Service (UPS)	July 2006	-16.96%
Tractor Supply (TSCO)	July 2006	-16.69%
NetApp (NTAP)	July 2006	-16.53%
Juniper Networks (JNPR)	July 2006	-16.46%
Pentair (PNR)	July 2006	-16.07%
Eaton (ETN)	July 2006	-15.16%