Synchrony Financial (SYF) had the lowest return in April 2017 by a US stock in the S&P 500 (GSPC), returning -19.3%.

ASSET	MONTH	% RETURN
Synchrony Financial (SYF)	April 2017	-19.3%
WW Grainger (GWW)	April 2017	-17.2%
Enphase Energy (ENPH)	April 2017	-14.39%
United Rentals (URI)	April 2017	-12.35%
Fastenal (FAST)	April 2017	-12.09%
Cardinal Health (CAH)	April 2017	-11.18%
Tractor Supply (TSCO)	April 2017	-10.18%
F5 Networks (FFIV)	April 2017	-9.53%
Vistra Energy (VST)	April 2017	-9.34%
CF Industries (CF)	April 2017	-9.11%
Advanced Micro Devices (AMD)	April 2017	-8.9%
NRG Energy (NRG)	April 2017	-8.88%
ON Semiconductor (ON)	April 2017	-8.81%
Discover Financial Services (DFS)	April 2017	-8.59%
DexCom (DXCM)	April 2017	-8.01%
Incyte (INCY)	April 2017	-7.94%
Mosaic (MOS)	April 2017	-7.93%
International Business Machines (IBM)	April 2017	-7.78%
Seagate Technology (STX)	April 2017	-7.67%
Capital One Financial (COF)	April 2017	-7.48%
LyondellBasell Industries (LYB)	April 2017	-7.36%
Schlumberger (SLB)	April 2017	-7.29%
Halliburton (HAL)	April 2017	-7.24%
CoreSite Realty (COR)	April 2017	-7.19%
Analog Devices (ADI)	April 2017	-7.1%