Laboratory Corporation of America (LH) had the highest return between 1990 and 1993 by a US stock in the S&P 500 (GSPC), returning 5,860,600%.

ASSET	YEARS	% RETURN
Laboratory Corporation of America (LH)	1990-1993	5,860,600%
Jack Henry & Associates (JKHY)	1990-1993	3,339.53%
Cisco Systems (CSCO)	1990-1993	2,223.83%
Electronic Arts (EA)	1990-1993	1,271.43%
UnitedHealth (UNH)	1990-1993	1,143.15%
Best Buy (BBY)	1990-1993	1,015.89%
PTC (PTC)	1990-1993	1,007.15%
Lam Research (LRCX)	1990-1993	807.44%
Bio-Techne (TECH)	1990-1993	665.56%
Constellation Brands Inc Class A (STZ)	1990-1993	608.75%
Southwest Airlines (LUV)	1990-1993	602.97%
Waste Management (WM)	1990-1993	574.1%
Smith AO (AOS)	1990-1993	543.19%
Amgen (AMGN)	1990-1993	503.05%
Charles Schwab (SCHW)	1990-1993	433.71%
Applied Materials (AMAT)	1990-1993	429.98%
Microchip Technology (MCHP)	1990-1993	424.48%
Home Depot (HD)	1990-1993	375.83%
Micron Technology (MU)	1990-1993	368.6%
IDEXX Laboratories (IDXX)	1990-1993	337.36%
Lowe's Companies (LOW)	1990-1993	330.56%
Paychex (PAYX)	1990-1993	317.36%
Microsoft (MSFT)	1990-1993	315.8%
Roper Technologies (ROP)	1990-1993	311.18%
Fastenal (FAST)	1990-1993	305.49%