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Senate Banking Hearing On Equity Market Structure And Electronic Trading
Kenneth Griffin, founder and chief executive officer of Citadel LLC, speaks during a Senate Banking Committee hearing in Washington, D.C., U.S., on Tuesday, July 8, 2014.
Bloomberg—Bloomberg via Getty Images

Maybe it was the ghost of Bernie Sanders. Last year, the world's most successful hedge fund managers got stupendously rich at a slightly slower pace than they have in the past.

The top-25 highest earners took home a combined $13 billion in 2015, according to the industry's annual "rich list" compiled by Institutional Investor's Alpha. The top two, Citadel’s Kenneth Griffin and Renaissance Technologies' James Simons, both took home $1.7 billion, according to the publication, which tallies the annual earnings of the industry's top earners. The median earnings among the top 25 was $275 million.

While it may be hard to get your head around, those earnings are actually a bit of a come down from several years ago when some star managers, having navigated the financial crisis, seemed to have the Midas touch. In 2013, the top 25 raked in a whopping $21 billion. In 2009, it was $25 billion. James Simons -- a perennial on the list -- made $2.5 billion in 2009.

Hedge funds, which hold about $2.9 trillion in assets, are lightly regulated and often secretive investment vehicles open to wealthy individuals and institutional investors like university endowments and public pension funds.

So what happened last year? Blame middling performance for the hedge fund industry and decisions by large institutional investors like pension funds to direct investment dollars to other, less pricey alternatives.

The 2015 earnings, as reported by the Institutional Investor, are more akin to fluctuations in the managers net worth -- like measuring Mark Zuckerberg's annual earnings based on Facebook stock price gains -- than a read on the manager's annual pay. That's because the publication counts not only the fees managers earned for managing clients money, but also the investment profits that these star investors reap on their own money invested in the funds they manage. Many managers keep the bulk of their personal wealth in their own funds. (After all, would you trust one that didn't?)

Hedge funds reached the height of their mystique in the years just following the financial crisis. That's because the funds' returns -- unlike your 401(k) -- don't need to be linked directly to stock and bond fluctuations. A lucky few managers -- like the ones depicted in The Big Short -- even managed to bet against stock and bond markets, profiting handsomely from the market's collapse. Since then, fewer funds have managed to shoot out the lights. Roughly half of all hedge funds lost money last year, according to Institutional Investor, including John Paulson, the most famous mortgage market short of all.

As a result of that middling performance -- not to mention public distaste for hedge funds' famously high fees and tax loopholes (h/t Bernie Sanders) -- a number of pension funds and endowments, long hedge funds' biggest customers, have been pulling money out in recent months. That will only make it harder for star managers to recapture their former glory.