NET WORTH: $8.7 billion The financial whiz famous for hiring PhDs to help run hedge funds, Simons is the highest ranked hedge fund manager taking the Buffett/Gates pledge -- though one more hedge fund manager rounds out the charitable giving Top 10. The other member of the hedge fund in the Buffett/Gates Top 10 is Arnold. In all, there are five hedge fund managers taking the Buffett/Gates pledge, with assets worth more than $15 billion -- though Simon alone represents more than half of the hedge fund pledges. Hedge fund managers have worked in overdrive to change their reputation from ruthless trading machines hell-bent on profits to that of socially minded capitalists. Yet it's not just Chinese billionaires, but Warren Buffett's right hand man no less, who questions some aspects of philanthropy. When the Buffett/Gates group of donors was first announced, one notable absent U.S. billionaire was Buffett's right hand man and vice chairman of Berkshire Hathaway, Charlie Munger. Munger has previously stated that his approach to charity differs from Buffett's, in giving away a lot of money throughout his life, as opposed to a majority of his wealth after death. Munger has donated heavily to education in the past. Now video of a speech given by Munger at the University of Michigan and tracked down by Bloomberg shows that while Munger and Buffett agree on much, how to dole out their fortunes is not the only manner in which they differ over the issue of charity. "I believe Costco does more for civilization than the Rockefeller Foundation," Munger is quoted as saying in the Internet video. "You get a bunch of very intelligent people sitting around trying to do good, I immediately get kind of suspicious and squirm in my seat." Munger is a Costco director. Munger also took some pot shots at the World Bank, saying, "I've seen so much folly and stupidity on the part of our major philanthropic groups, including the World Bank...I really have more confidence in building up the more capitalistic ventures like Costco."