Nutex Health (NUTX) had the highest return between 2013 and 2014 by a small-cap US stock, returning 399,900.1%.

ASSET	YEARS	% RETURN
Nutex Health (NUTX)	2013-2014	399,900.1%
Xpel (XPEL)	2013-2014	1,549.73%
Andretti Acquisition Corp II Class A Ordinary Shares (POLE)	2013-2014	896.73%
BioCryst Pharmaceuticals (BCRX)	2013-2014	664.78%
Canadian Solar (CSIQ)	2013-2014	591.14%
NioCorp Developments Ltd Common Stock (NB)	2013-2014	550.24%
Willdan (WLDN)	2013-2014	507.66%
Avadel Pharmaceuticals (AVDL)	2013-2014	472.91%
Universal Insurance (UVE)	2013-2014	407.51%
Build-A-Bear Workshop (BBW)	2013-2014	406.3%
Gray Television (GTN.A)	2013-2014	402.77%
Pacira BioSciences (PCRX)	2013-2014	399.21%
Gray Television (GTN)	2013-2014	391.22%
ArcBest (ARCB)	2013-2014	382.02%
Motorcar Parts of America (MPAA)	2013-2014	373.21%
Empresa Distribuidora y Comercializadora Norte SA ADR (EDN)	2013-2014	368.5%
Covenant Logistics (CVLG)	2013-2014	365.01%
Omeros (OMER)	2013-2014	351.37%
Pacific Biosciences of California (PACB)	2013-2014	348%
MGP Ingredients (MGPI)	2013-2014	340.01%
Old Second Bancorp (OSBC)	2013-2014	329.59%
Vanda Pharmaceuticals (VNDA)	2013-2014	278.84%
Independent Bank (IBCP)	2013-2014	277.1%
American Coastal Insurance (ACIC)	2013-2014	267.78%
Allient (ALNT)	2013-2014	266.24%

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