Warren Buffett is about to make a quick $12 billion. Buffett’s Berkshire Hathaway will become the biggest shareholder in Bank of America, the second-largest bank in the U.S. Berkshire Hathaway Inc. invoked its right to acquire 700 million shares of Bank of America Corp, taking roughly 7% ownership stake worth about $17 billion. Bank of America will become one of Berkshire’s biggest investments, along with Apple Inc., Coca-Cola, Kraft Heinz, and Wells Fargo.