The Oracle of Omaha has sent nearly $7.2 billion worth of his favorite bank stock to the chopping block over the last eight weeks.Few investors have the ability to command the attention of Wall Street professionals and everyday investors quite like Berkshire Hathaway (BRK.A -0.54%) (BRK.B -0.72%) CEO Warren Buffett. The reason is simple: He's crushed Wall Street's benchmark indexes over a span of nearly six decades.Since taking the reins in the mid 1960s, the Oracle of Omaha has overseen a cumulative return ...