Buffett's Berkshire Hathaway (BRK.A.N, BRK.B.N) announced its third reduction in Bank of America stock this month, selling over $3 billion in total. Berkshire Hathaway has been investing in Bank of America since 2011 and has long been the largest shareholder. According to documents submitted to regulatory authorities on Monday, Berkshire Hathaway sold $767 million worth of Bank of America stock between July 25th and July 29th. Combined with the scale of sales before this month, Berkshire Hathaway reduced its holdings by a total of 6.9%. However, the documents show that Berkshire Hathaway still holds nearly 962 million shares of Bank of America stock, valued at $39.5 billion based on Monday's closing price.