Billionaire investor Warren Buffett, who came to the aid of a struggling Bank of America back in 2011 with a $5 billion investment, has turned that into a paper profit of more than $11 billion after exercising his right to buy 700 million shares of the bank's common stock at a bargain-basement price. After Tuesday's market close, Bank of America confirmed in a press release that Buffett's Berkshire Hathaway had exercised its warrants to buy 700 million of the bank's common stock at $7.14 per share, a steep discount to the bank's Tuesday's closing price of $23.58. Mr. Buffett said earlier this year that Berkshire planned to make the switch in its Bank of America stake if the bank could increase its annual dividend to 44 cents a share from 30 cents a share. REUTERS/Rick Wilking/File Photo

Berkshire is now the largest shareholder in the second- and third-largest U.S. banks, with stakes of roughly 6.6 percent in Bank of America and 10 percent in Wells Fargo & Co (WFC.N), according to Reuters data.
Berkshire Hathaway Inc has become the largest shareholder of Bank of America by exercising its right to acquire 700 million shares at a steep discount, more than tripling an investment it made six years ago. Bank of America on Tuesday announced the exercise of the warrants, which gave Berkshire, controlled by Warren Buffett, the right to buy the bank’s shares for about $7.14 each. Bank of America shares closed down 14 cents at $23.58 on the same day.