Advanced Micro Devices (AMD) had the highest return in April 1993 by a mega-cap US stock, returning 22.3%.

ASSET	MONTH	% RETURN
Advanced Micro Devices (AMD)	April 1993	22.28%
Toyota Motor Corporation ADR (TM)	April 1993	18.22%
Caterpillar (CAT)	April 1993	16.88%
Shell PLC ADR (SHEL)	April 1993	9.91%
Novo Nordisk A-S (NVO)	April 1993	5.93%
Mitsubishi UFJ Financial Group Inc ADR (MUFG)	April 1993	5.71%
Merck (MRK)	April 1993	5.34%
UnitedHealth (UNH)	April 1993	4.86%
Raytheon Technologies (RTX)	April 1993	4.23%
Chevron (CVX)	April 1993	3.92%
American Express (AXP)	April 1993	3.7%
Johnson & Johnson (JNJ)	April 1993	2.35%
Morgan Stanley (MS)	April 1993	2.31%
Wells Fargo (WFC)	April 1993	1.73%
Eli Lilly and (LLY)	April 1993	1.54%
GE Aerospace (GE)	April 1993	1.26%
Applied Materials (AMAT)	April 1993	0.3%
Thermo Fisher Scientific (TMO)	April 1993	0%
Apple (AAPL)	April 1993	-0.03%
Exxon Mobil (XOM)	April 1993	-0.19%
Lam Research (LRCX)	April 1993	-0.4%
Citigroup (C)	April 1993	-0.81%
Berkshire Hathaway (BRK.A)	April 1993	-1.17%
Procter & Gamble (PG)	April 1993	-1.93%
Micron Technology (MU)	April 1993	-2.13%

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