Warren Buffett is an 81-year-old American businessman, investor and philanthropist who is the chairman and CEO of Berkshire Hathaway. He has a net worth of $44 billion as of 2012. Berkshire Hathaway is a multinational conglomerate holding company and the 8th largest public company in the world. Buffett has demonstrated tremendous discipline in valuing businesses and transcends the school of Benjamin Graham. He enjoys a normal lifestyle without extravagance and has pledged to give away 85% of his wealth to philanthropy.