Warren Buffett’s Berkshire Hathaway has reduced its stake in Bank of America to below 10%, selling over 9 million shares in a three-day period this week. The stake now stands at approximately 9%. As Berkshire no longer holds more than 10% of Bank of America’s shares, the company is no longer required to disclose transactions as frequently under SEC rules. Bank of America remains Berkshire's largest institutional holding. Bank of America shares have risen about 1% in the past month despite the sales.