ASML Holding NV ADR (ASML) had the highest return in October 1995 by a mega-cap US stock, returning 24.8%.

ASSET	MONTH	% RETURN
ASML Holding NV ADR (ASML)	October 1995	24.84%
Oracle (ORCL)	October 1995	12.94%
Cisco Systems (CSCO)	October 1995	12.32%
Johnson & Johnson (JNJ)	October 1995	10.7%
Microsoft (MSFT)	October 1995	10.5%
UnitedHealth (UNH)	October 1995	9.82%
Eli Lilly and (LLY)	October 1995	8.26%
McDonald’s (MCD)	October 1995	7.54%
Procter & Gamble (PG)	October 1995	6.07%
Exxon Mobil (XOM)	October 1995	5.89%
Novo Nordisk A-S (NVO)	October 1995	5.75%
Coca-Cola (KO)	October 1995	4.17%
AstraZeneca PLC ADR (AZN)	October 1995	2.5%
International Business Machines (IBM)	October 1995	2.37%
LIN TV (LIN)	October 1995	1.89%
Merck (MRK)	October 1995	1.55%
Raytheon Technologies (RTX)	October 1995	0.57%
Toyota Motor Corporation ADR (TM)	October 1995	0.34%
Shell PLC ADR (SHEL)	October 1995	0.1%
Berkshire Hathaway (BRK.A)	October 1995	0%
Caterpillar (CAT)	October 1995	-0.22%
GE Aerospace (GE)	October 1995	-0.39%
Costco Wholesale (COST)	October 1995	-0.73%
Royal Bank of Canada (RY)	October 1995	-1.19%
Thermo Fisher Scientific (TMO)	October 1995	-1.34%

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