SurgePays (SURG) had the highest return in May 2017 by a US stock, returning 205.7%.

ASSET	MONTH	% RETURN
SurgePays (SURG)	May 2017	205.72%
Netcapital (NCPL)	May 2017	200%
GlycoMimetics (GLYC)	May 2017	190.39%
BTCS (BTCS)	May 2017	105.44%
ANGI Homeservices (ANGI)	May 2017	104.07%
HIVE Blockchain Technologies (HIVE)	May 2017	100%
Clean Energy Technologies, Inc Common Stock (CETY)	May 2017	96.72%
SPI Energy (SPI)	May 2017	90.14%
Pieris Pharmaceuticals (PIRS)	May 2017	87.7%
Puma Biotechnology (PBYI)	May 2017	87.5%
Everspin Technologies (MRAM)	May 2017	79.8%
Reliance Global (RELI)	May 2017	78.71%
MannKind (MNKD)	May 2017	75.91%
Telix Pharmaceuticals Limited American Depositary Shares (TLX)	May 2017	73.11%
Workhorse (WKHS)	May 2017	71.71%
Intrusion (INTZ)	May 2017	70.41%
Camtek (CAMT)	May 2017	67.9%
authID (AUID)	May 2017	67.06%
Data I/O (DAIO)	May 2017	66.25%
Firefly Neuroscience (AIFF)	May 2017	64.71%
Shuttle Pharmaceuticals (SHPH)	May 2017	60%
InnovAge (INNV)	May 2017	58.55%
Sangamo Therapeutics (SGMO)	May 2017	54.55%
Lixte Biotechnology (LIXT)	May 2017	53.85%
PetMed Express (PETS)	May 2017	51.47%