25 hedge managers made $13 billion in 2015. The rich becoming richer?

The top five managers raked in more than $1 billion each. The results come amid an election season in which inequality has taken center stage. 

It appears that the rich are getting richer – 25 of them, anyway, if top hedge fund managers' earnings are anything to go by.

About half of all hedge funds lost money in 2015, but the funds' top employees' take-homes tell a different story. The top 25 earned a combined $13 billion, 10 percent more than what the same-ranked group earned the previous year, according to rankings and a survey published Tuesday by the Institutional Investor's Alpha magazine. 

The top five managers raked in more than $1 billion each, accounting for more than half of the $13 billion. Kenneth Griffin, the founder of the Chicago-based Citadel hedge fund, topped the list for a second straight year, tying with James Simons of Renaissance Technologies. The two managers raked in $1.7 billion each.

Many top performers attributed their success to technology, as half of the managers in the top 25 used computer-generated investing strategies.

The results come amid an election season in which inequality has taken center stage, connected to conversations on education, discrimination, and trade policies, particularly resonating with Democratic voters. 

But Republicans haven’t been left out, either; during the party's first two presidential debates, the words "inequality," "disparity," "rich," "poor," and "middle class" made up just .06 percent of candidates' speech, but the rate tripled during the October 13 debate, according to a report from the communications and consulting firm Logos Consulting Group. 

Sen. Bernie Sanders of Vermont, in particular, has put inequality at the center of his campaign, often criticizing competitor Hillary Clinton for her presumed friendliness with Wall Street corporations.

It resonates strongly with US voters: Americans ranked inequality as the greatest global danger in a 2014 Global Attitudes and Trends study by Pew research Center, with 27 percent ranking it at the top, above religious and ethnic hatred. 67 percent of Americans are dissatisfied with the way income and wealth are distributed in the US, while only 31 percent said they are satisfied, according to a February poll from Gallup. 

And the wage gap between top chief executives and the average workers has widened, and may be even worse than Americans think. A majority of Americans believe that a CEOs makes 30 times what the average worker makes, according to a 2014 study conducted by the Harvard Business School.  But various studies have determined that figure to be at least 10 times higher than what Americans estimate.

The Economic Policy Institute, a left-leaning advocacy group in Washington, D.C., estimates that the top CEOs in the US make at least 300 times more than the average worker, a figure which has skyrocketed up from just 20 times as much in 1965. In 2014, for example, a CEO of a top company made over $16 million a year, compared to roughly $53,000 for an average employee.  

But some contend that that stark gap is actually decreasing. Rick Newman of the US News & World Report, for example, writes that numbers from the AFL-CIO show that the trend has been slowing down since the turn of the millennium: 

If you measure pay changes since 2000, average workers have actually done better than CEOs, according to the AFL-CIO numbers. After accounting for inflation, average-worker pay has risen by 4 percent since 2000, while CEO pay has fallen by 30 percent. Compared with levels right before the recession started, average-worker pay, adjusting for inflation, has gone up by 2.2 percent while CEO pay has risen by 5 percent.