Micron Technology (MU) had the highest return between 1993 and 1994 by a mega-cap US stock, returning 484.3%.

ASSET	YEARS	% RETURN
Micron Technology (MU)	1993-1994	484.25%
Oracle (ORCL)	1993-1994	212.4%
Caterpillar (CAT)	1993-1994	104.65%
Toyota Motor Corporation ADR (TM)	1993-1994	81.99%
Cisco Systems (CSCO)	1993-1994	78.4%
Berkshire Hathaway (BRK.A)	1993-1994	73.99%
UnitedHealth (UNH)	1993-1994	60.65%
International Business Machines (IBM)	1993-1994	49.08%
Microsoft (MSFT)	1993-1994	43.82%
American Express (AXP)	1993-1994	43.47%
AstraZeneca PLC ADR (AZN)	1993-1994	43.37%
Thermo Fisher Scientific (TMO)	1993-1994	42.82%
Chevron (CVX)	1993-1994	39.01%
Raytheon Technologies (RTX)	1993-1994	38.51%
Advanced Micro Devices (AMD)	1993-1994	38.2%
Shell PLC ADR (SHEL)	1993-1994	31.76%
Coca-Cola (KO)	1993-1994	27.17%
LIN TV (LIN)	1993-1994	26.95%
GE Aerospace (GE)	1993-1994	26.15%
McDonald’s (MCD)	1993-1994	21.62%
Procter & Gamble (PG)	1993-1994	20.55%
Eli Lilly and (LLY)	1993-1994	17.97%
Johnson & Johnson (JNJ)	1993-1994	14.4%
Wells Fargo (WFC)	1993-1994	14.27%
Abbott Laboratories (ABT)	1993-1994	12.53%

Mega-cap stocks are treated as having a market cap of $200B+.