There are 46 billionaires in the world who have made their fortunes managing hedge funds, but some of these financial traders are a little less rich than they were a year ago. Still, while the average hedge fund lost money in 2015, a majority of the hedge funds run by billionaires managed to produce gains last year—and some of them significantly beat the 1.4% return of the U.S. stock market as measured by the Standard & Poor’s 500 index.