Visa Inc Class A (V) had the highest return between February 1, 2011 and January 31, 2013 by a mega-cap US stock in the S&P 500 (GSPC), returning 128.5%.

ASSET	DATE	% RETURN
Visa Inc Class A (V)	2/1/2011 - 1/31/2013	128.48%
Mastercard (MA)	2/1/2011 - 1/31/2013	126.11%
Home Depot (HD)	2/1/2011 - 1/31/2013	90.65%
Eli Lilly and (LLY)	2/1/2011 - 1/31/2013	70.35%
Abbott Laboratories (ABT)	2/1/2011 - 1/31/2013	66.62%
Philip Morris International (PM)	2/1/2011 - 1/31/2013	64.4%
Amazon (AMZN)	2/1/2011 - 1/31/2013	55.7%
Costco Wholesale (COST)	2/1/2011 - 1/31/2013	55.35%
Tesla (TSLA)	2/1/2011 - 1/31/2013	54.3%
AT&T (T)	2/1/2011 - 1/31/2013	43.89%
Walt Disney (DIS)	2/1/2011 - 1/31/2013	42.48%
Merck (MRK)	2/1/2011 - 1/31/2013	41.55%
American Express (AXP)	2/1/2011 - 1/31/2013	39.09%
UnitedHealth (UNH)	2/1/2011 - 1/31/2013	37.22%
McDonald’s (MCD)	2/1/2011 - 1/31/2013	36.52%
Apple (AAPL)	2/1/2011 - 1/31/2013	34.64%
Johnson & Johnson (JNJ)	2/1/2011 - 1/31/2013	33.07%
Salesforce (CRM)	2/1/2011 - 1/31/2013	32.39%
Walmart (WMT)	2/1/2011 - 1/31/2013	30.63%
International Business Machines (IBM)	2/1/2011 - 1/31/2013	29.53%
Chevron (CVX)	2/1/2011 - 1/31/2013	28.4%
Broadcom (AVGO)	2/1/2011 - 1/31/2013	27.43%
Blackstone (BX)	2/1/2011 - 1/31/2013	26.7%
Thermo Fisher Scientific (TMO)	2/1/2011 - 1/31/2013	26.63%
Procter & Gamble (PG)	2/1/2011 - 1/31/2013	26.55%

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