Paycom Soft (PAYC) had the highest return in August 2015 by a US stock in the S&P 500 (GSPC), returning 20.4%.

ASSET	MONTH	% RETURN
Paycom Soft (PAYC)	August 2015	20.4%
Best Buy (BBY)	August 2015	14.06%
NVIDIA (NVDA)	August 2015	12.24%
Caesars Entertainment (CZR)	August 2015	11.88%
Incyte (INCY)	August 2015	11.42%
DexCom (DXCM)	August 2015	10.75%
Sysco (SYY)	August 2015	10.69%
Motorola Solutions (MSI)	August 2015	7.89%
Martin Marietta Materials (MLM)	August 2015	7.39%
First Solar (FSLR)	August 2015	7.02%
Constellation Brands Inc Class A (STZ)	August 2015	6.39%
JM Smucker (SJM)	August 2015	6.3%
Tyson Foods (TSN)	August 2015	5.92%
CDW (CDW)	August 2015	5.74%
Fidelity National Information Services (FIS)	August 2015	5.44%
Occidental Petroleum (OXY)	August 2015	5.1%
Expeditors International of Washington (EXPD)	August 2015	4.7%
Amun Bitwise Select 10 Large Cap Crypto ETP (KEYS)	August 2015	4.33%
United Rentals (URI)	August 2015	4.32%
MGM Resorts International (MGM)	August 2015	4.29%
Hormel Foods (HRL)	August 2015	4%
Super Micro Computer (SMCI)	August 2015	3.21%
Vulcan Materials (VMC)	August 2015	2.91%
Leidos (LDOS)	August 2015	2.83%
EOG Resources (EOG)	August 2015	2.77%