Netflix (NFLX) had the highest return in January 2004 by a mega-cap US stock, returning 27.7%.

ASSET	MONTH	% RETURN
Netflix (NFLX)	January 2004	27.72%
Micron Technology (MU)	January 2004	17.42%
Thermo Fisher Scientific (TMO)	January 2004	10.6%
GE Aerospace (GE)	January 2004	8.48%
American Express (AXP)	January 2004	7.04%
International Business Machines (IBM)	January 2004	6.86%
Taiwan Semiconductor Manufacturing (TSM)	January 2004	6.68%
JPMorgan Chase (JPM)	January 2004	6.37%
Berkshire Hathaway (BRK.A)	January 2004	6.22%
Berkshire Hathaway (BRK.B)	January 2004	5.9%
Cisco Systems (CSCO)	January 2004	5.54%
Apple (AAPL)	January 2004	4.7%
Oracle (ORCL)	January 2004	4.6%
Intuitive Surgical (ISRG)	January 2004	3.97%
Johnson & Johnson (JNJ)	January 2004	3.41%
McDonald’s (MCD)	January 2004	3.17%
UnitedHealth (UNH)	January 2004	3.1%
Walt Disney (DIS)	January 2004	2.17%
Bank of America (BAC)	January 2004	2.14%
Procter & Gamble (PG)	January 2004	1.91%
Citigroup (C)	January 2004	1.7%
Goldman Sachs (GS)	January 2004	1.01%
Morgan Stanley (MS)	January 2004	0.99%
Raytheon Technologies (RTX)	January 2004	0.75%
Microsoft (MSFT)	January 2004	0.25%

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