Frontline (FRO) had the lowest return in May 2014 by a US stock in the Energy Sector, returning -33.5%.

ASSET	MONTH	% RETURN
Frontline (FRO)	May 2014	-33.53%
Vaalco Energy (EGY)	May 2014	-29.35%
W&T Offshore (WTI)	May 2014	-22.99%
Energy Services Of America (ESOA)	May 2014	-22.84%
Recon Technology (RCON)	May 2014	-18.96%
Core Laboratories (CLB)	May 2014	-14.63%
Houston American Energy (HUSA)	May 2014	-14%
Matador Resources (MTDR)	May 2014	-13.25%
Alto Ingredients (ALTO)	May 2014	-13.13%
Expro (XPRO)	May 2014	-12.59%
Geospace Technologies (GEOS)	May 2014	-12.57%
Riley Exploration Permian (REPX)	May 2014	-10.63%
Gevo (GEVO)	May 2014	-10.48%
Denison Mines (DNN)	May 2014	-10.22%
Natural Resource Partners (NRP)	May 2014	-10.09%
Innovex International (INVX)	May 2014	-9.84%
Talos Energy (TALO)	May 2014	-9.43%
Dawson Geophysical (DWSN)	May 2014	-9.41%
NexGen Energy (NXE)	May 2014	-8.85%
USA Compression Partners (USAC)	May 2014	-8.59%
Tetra Technologies (TTI)	May 2014	-7.91%
Navigator (NVGS)	May 2014	-7.78%
Contura Energy (CTRA)	May 2014	-7.64%
Kolibri Global Energy Inc Common stock (KGEI)	May 2014	-6.91%
Antero Resources (AR)	May 2014	-6.35%