CareDx (CDNA) had the highest return in August 2017 by a small-cap US stock, returning 111.9%.

ASSET	MONTH	% RETURN
CareDx (CDNA)	August 2017	111.85%
Nutex Health (NUTX)	August 2017	91.01%
Almonty Industries Inc Common Shares (ALM)	August 2017	67.23%
Tandem Diabetes Care (TNDM)	August 2017	64.71%
Veritone (VERI)	August 2017	63.96%
MannKind (MNKD)	August 2017	55.64%
Calumet Specialty Products Partners (CLMT)	August 2017	53.85%
XOMA (XOMA)	August 2017	53.81%
Dolly Varden Silver (DVS)	August 2017	53.07%
Pacific Biosciences of California (PACB)	August 2017	51.84%
Manitowoc (MTW)	August 2017	44.13%
Evotec SE ADR (EVO)	August 2017	38.85%
Americas Silver (USAS)	August 2017	38.41%
Genco Shipping & Trading (GNK)	August 2017	36.11%
CorMedix (CRMD)	August 2017	35.62%
BioLife Solutions (BLFS)	August 2017	35.43%
QuinStreet (QNST)	August 2017	34.09%
Vericel Corp Ord (VCEL)	August 2017	32.31%
UroGen Pharma (URGN)	August 2017	32.06%
Global Industrial (GIC)	August 2017	31.54%
Corvus Pharmaceuticals (CRVS)	August 2017	30.72%
Yelp (YELP)	August 2017	30.28%
Xunlei Ltd Adr (XNET)	August 2017	29.66%
Gravity (GRVY)	August 2017	29.03%
CytomX Therapeutics (CTMX)	August 2017	27.72%

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