Salient to Investors:
The S&P 500 is not a measure of the American economy and U.S. stocks because it is global due to the multinationals included in the index.
The S&P 500 is not broadly diversified because it is market cap-weighted. Tech is 20 percent, Apple near 5% , Exxon Mobil near 3%.
An S&P indexed fund is not sufficient diversification because it omits important segments of the market, like foreign-based companies, smaller companies with bigger growth potential, REITs, bonds, commodities, real estate.
Not all S&P 500 Index funds are cheap and perform the same.
Read the full article at http://www.investorplace.com/2012/09/5-ugly-myths-about-the-sp-500/2/