Claim: Warren Buffett is a shareholder.

Warren Edward Buffett -LRB- -LSB- ˈbʌfᵻt -RSB- born August 30 , 1930 -RRB- is an American business magnate , investor , and philanthropist . He is considered by some to be one of the most successful investors in the world , and as of March 2017 is the second wealthiest person in the United States , and the fourth wealthiest in the world , with a total net worth of $ 73.3 billion .   Born in Omaha , Buffett developed an interest in business and investing in his youth , eventually entering the Wharton School of the University of Pennsylvania in 1947 before transferring and graduating from University of Nebraska -- Lincoln . After graduating at 19 , Buffett enrolled at Columbia Business School of Columbia University , learning and eventually creating his investment philosophy around a concept pioneered by Benjamin Graham -- value investing . He attended New York Institute of Finance to specialize his economics background and soon after began various business partnerships , including one with Graham . After meeting Charlie Munger , Buffett created the Buffett Partnership . His firm would eventually acquire a textile manufacturing firm called Berkshire Hathaway and assume its name to create a diversified holding company .   Buffett has been the chairman and largest shareholder of Berkshire Hathaway since 1970 , and his business exploits have had him referred to as the `` Wizard '' , `` Oracle '' or `` Sage '' of Omaha by global media outlets . He is noted for his adherence to value investing and for his personal frugality despite his immense wealth .   Buffett is a notable philanthropist , having pledged to give away 99 percent of his fortune to philanthropic causes , primarily via the Bill & Melinda Gates Foundation . In 2009 , with Bill Gates and Mark Zuckerberg , Warren founded The Giving Pledge , whereby billionaires pledge to give away at least half of their fortunes .   He is also active in contributing to political causes , having endorsed Democratic candidate Hillary Clinton in the 2016 U.S. presidential election ; he has publicly opposed the policies , actions , and statements of the current U.S. president , Donald Trump .