Caesars Entertainment (CZR) had the lowest return in March 2013 by a US stock in the S&P 500 (GSPC), returning -12.5%.

ASSET	MONTH	% RETURN
Caesars Entertainment (CZR)	March 2013	-12.47%
Intuitive Surgical (ISRG)	March 2013	-11.18%
Juniper Networks (JNPR)	March 2013	-9.96%
Cardinal Health (CAH)	March 2013	-9.26%
Ulta Beauty (ULTA)	March 2013	-8.03%
Expeditors International of Washington (EXPD)	March 2013	-7.22%
Apollo Global Management LLC Class A (APO)	March 2013	-7%
FedEx (FDX)	March 2013	-6.45%
Lululemon Athletica (LULU)	March 2013	-6.27%
Celanese (CE)	March 2013	-5.63%
F5 Networks (FFIV)	March 2013	-5.46%
Facebook (META)	March 2013	-5.43%
Expedia (EXPE)	March 2013	-5.3%
Oracle (ORCL)	March 2013	-5.25%
Caterpillar (CAT)	March 2013	-4.99%
NXP Semiconductors (NXPI)	March 2013	-4.87%
Monster Beverage (MNST)	March 2013	-4.79%
FactSet Research Systems (FDS)	March 2013	-4.7%
FMC (FMC)	March 2013	-4.68%
CF Industries (CF)	March 2013	-4.6%
Edwards Lifesciences (EW)	March 2013	-4.22%
MarketAxess (MKTX)	March 2013	-4.16%
Akamai Technologies (AKAM)	March 2013	-3.76%
Rockwell Automation (ROK)	March 2013	-3.76%
Royal Caribbean Cruises (RCL)	March 2013	-3.71%