Eyepoint Pharmaceuticals (EYPT) had the highest return in April 2018 by a small-cap US stock, returning 105%.

ASSET	MONTH	% RETURN
Eyepoint Pharmaceuticals (EYPT)	April 2018	105%
Solid Biosciences LLC (SLDB)	April 2018	90.93%
American Battery Technology Company Common Stock (ABAT)	April 2018	71.43%
Relmada Therapeutics (RLMD)	April 2018	64.04%
Tandem Diabetes Care (TNDM)	April 2018	53.21%
Contango ORE (CTGO)	April 2018	47.45%
BTQ Technologies Corp Common Stock (BTQ)	April 2018	40.91%
Verastem (VSTM)	April 2018	39.46%
Caledonia Mining (CMCL)	April 2018	39.27%
W&T Offshore (WTI)	April 2018	38.64%
Oil States International (OIS)	April 2018	38%
Valhi (VHI)	April 2018	37.19%
Helix Energy Solutions (HLX)	April 2018	35.68%
Ovid Therapeutics (OVID)	April 2018	34.66%
BioLife Solutions (BLFS)	April 2018	31.45%
NPK International (NPKI)	April 2018	30.43%
Digi Power X (DGXX)	April 2018	30.3%
Harrow Health (HROW)	April 2018	30.29%
Pulse Biosciences (PLSE)	April 2018	30.2%
Expro (XPRO)	April 2018	29.93%
Xunlei Ltd Adr (XNET)	April 2018	29.64%
Omeros (OMER)	April 2018	29.05%
Orthopediatrics (KIDS)	April 2018	28.9%
Precision Drilling (PDS)	April 2018	28.52%
Rezolute (RZLT)	April 2018	28.32%

Small-cap stocks are treated as having a market cap between $300M and $2B.