Kraft Heinz (KHC) had the highest return in March 2015 by a US stock in the S&P 500 (GSPC), returning 35.8%.

ASSET	MONTH	% RETURN
Kraft Heinz (KHC)	March 2015	35.8%
Centene (CNC)	March 2015	15.11%
Cooper Companies, Inc Common Stock (COO)	March 2015	14.04%
CBRE Group Inc Class A (CBRE)	March 2015	12.73%
ResMed (RMD)	March 2015	11.43%
Skyworks Solutions (SWKS)	March 2015	11.39%
Builders FirstSource (BLDR)	March 2015	10.98%
CoreSite Realty (COR)	March 2015	10.82%
Steel Dynamics (STLD)	March 2015	10.6%
West Pharmaceutical Services (WST)	March 2015	10.01%
Rollins (ROL)	March 2015	9.98%
Quest Diagnostics (DGX)	March 2015	9.33%
Norwegian Cruise Line (NCLH)	March 2015	9.24%
MSCI (MSCI)	March 2015	9.01%
DaVita HealthCare Partners (DVA)	March 2015	9.01%
ONEOK (OKE)	March 2015	8.99%
Caesars Entertainment (CZR)	March 2015	8.87%
Humana (HUM)	March 2015	8.66%
Carnival (CCL)	March 2015	8.65%
STERIS (STE)	March 2015	8.64%
Revvity (RVTY)	March 2015	8.55%
Regeneron Pharmaceuticals (REGN)	March 2015	8.46%
Diamondback Energy (FANG)	March 2015	8.39%
Darden Restaurants (DRI)	March 2015	8.28%
Kroger (KR)	March 2015	7.94%