The chart above shows the annual returns on the S&P 500 index and the average annual returns on a comprehensive index of thousands of hedge funds maintained by Barclay over the period of Buffett's bet: From January 2008 through December of 2017. A $100,000 investment at the beginning of 2008 would have more than doubled to about $225,586 at the end of last year, compared to only about $148,000 invested in the average hedge fund.