Buffett put his money behind his long-held argument that "experts" don't do better than the stock market as a whole. It's the basis of his argument that the fees "helpers" charge investors usually aren't justified.
In a Fortune piece, long-time Buffett friend Carol Loomis writes that after six years the fund Buffett selected for the wager, the Vanguard 500 Index Fund Admiral Shares, was up 43.8 percent at the end of 2013.
The other side of the bet is a collection of five hedge funds of funds chosen by New York-based Protégé Partners.
After all fees, their average gain was about 12.5 percent. The names of the funds have not been revealed.