The shining star of the stock market for 2012 so far has to be the mega-caps. As Paul Lim pointed out in yesterday's New York Times, the 50 biggest American stocks in terms of market capitalization - as measured by the Russell Top 50 index - have risen by more than 14 percent so far this year. The Russell 2000, made up of small-cap stocks, is up just 1 percent. In July alone, a tough month for most of the market, the mega-caps are up 2 percent, while the small caps have dropped by 1 percent.