Monster Beverage (MNST) had the highest return in March 1990 by a US stock, returning 77%.

ASSET	MONTH	% RETURN
Monster Beverage (MNST)	March 1990	76.99%
Repro Med Systems (KRMD)	March 1990	70.45%
InterDigital (IDCC)	March 1990	62.16%
Waste Management (WM)	March 1990	54.04%
Flanigans Enterprises (BDL)	March 1990	53.83%
Powell Industries (POWL)	March 1990	36%
Super X AI Technology Limited - Ordinary Shares (SUPX)	March 1990	33.33%
Pure Cycle (PCYO)	March 1990	33.33%
GEE (JOB)	March 1990	31.82%
Smith AO (AOS)	March 1990	31.25%
SkyWest (SKYW)	March 1990	31.11%
American Shared Hospital Service (AMS)	March 1990	30.44%
Best Buy (BBY)	March 1990	29.65%
Team (TISI)	March 1990	29.55%
ODP (ODP)	March 1990	28.85%
Photronics (PLAB)	March 1990	28.57%
Lakeland Industries (LAKE)	March 1990	27.78%
Curtiss-Wright (CW)	March 1990	26.67%
Lowe's Companies (LOW)	March 1990	26.44%
Barnwell Industries (BRN)	March 1990	25.33%
Mesa Laboratories (MLAB)	March 1990	25.01%
Johnson Controls International (JCI)	March 1990	25%
McEwen Mining (MUX)	March 1990	25%
Adobe Systems (ADBE)	March 1990	24.79%
Valmont Industries (VMI)	March 1990	24.67%