NVIDIA (NVDA) had the highest return in March 2006 by a mega-cap US stock, returning 21.1%.

ASSET	MONTH	% RETURN
NVIDIA (NVDA)	March 2006	21.06%
Goldman Sachs (GS)	March 2006	10.55%
Oracle (ORCL)	March 2006	9.61%
Netflix (NFLX)	March 2006	8.12%
Cisco Systems (CSCO)	March 2006	6.33%
Alphabet Inc Class A (GOOGL)	March 2006	5.82%
GE Aerospace (GE)	March 2006	5.49%
Morgan Stanley (MS)	March 2006	5.23%
Costco Wholesale (COST)	March 2006	4.76%
Walmart Inc Common Stock (WMT)	March 2006	4.53%
Berkshire Hathaway (BRK.B)	March 2006	4.15%
Berkshire Hathaway (BRK.A)	March 2006	4.09%
Novartis AG ADR (NVS)	March 2006	2.97%
Toyota Motor Corporation ADR (TM)	March 2006	2.87%
International Business Machines (IBM)	March 2006	2.83%
Johnson & Johnson (JNJ)	March 2006	2.78%
Taiwan Semiconductor Manufacturing (TSM)	March 2006	2.76%
Mitsubishi UFJ Financial Group Inc ADR (MUFG)	March 2006	2.46%
Chevron (CVX)	March 2006	2.2%
LIN TV (LIN)	March 2006	2.16%
Exxon Mobil (XOM)	March 2006	2.13%
Citigroup (C)	March 2006	1.81%
Shell PLC ADR (SHEL)	March 2006	1.65%
Merck (MRK)	March 2006	1.62%
Royal Bank of Canada (RY)	March 2006	1.33%

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