Universal Insurance (UVE) had the highest return between 1993 and 1994 by a small-cap US stock, returning 1,095,500%.

ASSET	YEARS	% RETURN
Universal Insurance (UVE)	1993-1994	1,095,500%
Caledonia Mining (CMCL)	1993-1994	2,950.01%
Rogers (ROG)	1993-1994	252.21%
Cohu (COHU)	1993-1994	248.79%
Barrett Business Services (BBSI)	1993-1994	244.58%
Cadiz (CDZI)	1993-1994	219.23%
Photronics (PLAB)	1993-1994	176.74%
LSI Industries (LYTS)	1993-1994	161.98%
Wolverine World Wide (WWW)	1993-1994	161.24%
Park Ohio (PKOH)	1993-1994	157.5%
Park Electrochemical (PKE)	1993-1994	146.31%
Wabash National (WNC)	1993-1994	137.96%
Neogen (NEOG)	1993-1994	125.06%
Transcontinental Realty Investors (TCI)	1993-1994	120.37%
Seneca Foods Corp B (SENEB)	1993-1994	119.51%
NPK International (NPKI)	1993-1994	113.33%
Washington Trust Bancorp (WASH)	1993-1994	107.12%
Arrow Financial (AROW)	1993-1994	105.32%
ADTRAN (ADTN)	1993-1994	101.1%
Hallador Energy (HNRG)	1993-1994	100%
Great Southern Bancorp (GSBC)	1993-1994	95.59%
Mesabi Trust (MSB)	1993-1994	93.33%
ManpowerGroup (MAN)	1993-1994	93.22%
John Wiley & Sons (WLY)	1993-1994	88.97%
National HealthCare (NHC)	1993-1994	88.1%

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