Warren Edward Buffett is an American business magnate, investor, and philanthropist. He is widely considered the most successful investor of the 20th century. Buffett is the primary shareholder, chairman and CEO of Berkshire Hathaway and consistently ranked among the world's wealthiest people. He was ranked as the world's wealthiest person in 2008 and as the third wealthiest person in 2011. In 2012, American magazine Time named Buffett one of the most influential people in the world.
Buffett is called the "Wizard of Omaha", "Oracle of Omaha", or the "Sage of Omaha" and is noted for his adherence to the value investing philosophy and for his personal frugality despite his immense wealth. Buffett is also a notable philanthropist, having pledged to give away 99 percent of his fortune to philanthropic causes, primarily via the Gates Foundation. On April 11, 2012, he was diagnosed with prostate cancer, for which he completed treatment in September 2012.