Warren Buffett
Age: 80
Occupation: Investor, CEO of Berkshire Hathaway
Previous TIME 100 appearances: 2
Sure, the oracle of Omaha has long been recognized as one of the greatest financial minds of our time. But as he prepares to eventually hand over the reins of his conglomerate, Berkshire Hathaway, at some unspecified future date, Buffett's mind is turning to his $50 billion fortune, and in typical fashion he's decided that the only practical, ethical thing to do is to give it away. In the past year, however, the humble Midwesterner has decided to do something more radical: encourage others to follow his lead. Together with Bill Gates, Buffett has established the Giving Pledge, a campaign to get the world's wealthiest people to agree to give away the vast majority of their fortunes to philanthropic causes. So far some 60 billionaires and almost billionaires have signed up; promised donations from the first 40 alone add up to $125 billion.