Enphase Energy (ENPH) had the highest return in July 2014 by a US stock in the S&P 500 (GSPC), returning 21.3%.

ASSET	MONTH	% RETURN
Enphase Energy (ENPH)	July 2014	21.32%
Steel Dynamics (STLD)	July 2014	17.44%
HCA (HCA)	July 2014	15.12%
Warner Bros Discovery (WBD)	July 2014	14.61%
Cooper Companies, Inc Common Stock (COO)	July 2014	14.54%
Chipotle Mexican Grill (CMG)	July 2014	12.77%
Universal Health Services (UHS)	July 2014	11.19%
United Airlines (UAL)	July 2014	11.14%
Intuitive Surgical (ISRG)	July 2014	11.1%
Regeneron Pharmaceuticals (REGN)	July 2014	10.76%
VeriSign (VRSN)	July 2014	10.76%
Gilead Sciences (GILD)	July 2014	9.81%
Intel (INTC)	July 2014	9.36%
Nasdaq (NDAQ)	July 2014	8.74%
LyondellBasell Industries (LYB)	July 2014	8.09%
Facebook (META)	July 2014	7.5%
Skyworks Solutions (SWKS)	July 2014	7.38%
Royal Caribbean Cruises (RCL)	July 2014	7.3%
Western Digital (WDC)	July 2014	7.22%
Amgen (AMGN)	July 2014	6.7%
Marathon Petroleum (MPC)	July 2014	6.66%
NetApp (NTAP)	July 2014	6.45%
Texas Pacific Land Trust (TPL)	July 2014	6.01%
CoreSite Realty (COR)	July 2014	5.83%
International Business Machines (IBM)	July 2014	5.49%