The Oracle of Omaha has sold more stocks than he's purchased for a staggering 12 consecutive quarters.For the better part of the last six decades, Berkshire Hathaway's (BRK.A 0.50%)(BRK.B 0.39%) billionaire CEO Warren Buffett has made a habit of outperforming the benchmark S&P 500 (SNPINDEX: ^GSPC) on a total return basis, including dividends. Whereas Wall Street's most-followed index has returned in the neighborhood of 45,500%, with dividends, over the last 60 years, the Oracle of Omaha has overseen a cumu ...