An elite group of hedge fund managers once again proved they could literally make billions of dollars in a single year.
Six men made at least $1 billion in 2013, according to estimates from Forbes on the 25 highest-earning hedge fund managers and traders last year.
They are George Soros of family office Soros Fund Management ($4 billion); David Tepper of hedge fund firm Appaloosa Management ($3.5 billion); Steve Cohen of soon-to-be family office SAC Capital Advisors ($2.3 billion); John Paulson of hedge fund firm Paulson & Co. ($1.9 billion); Carl Icahn of activist investment shop Icahn Enterprises ($1.7 billion); and James Simons, the retired founder of quantitative trading hedge fund firm Renaissance Technologies ($1.1 billion).
Rounding out the top 10 of the Forbes list were four other hedge fund managers: Ray Dalio of macroeconomic-focused Bridgewater Associates ($900 million); Ken Griffin of multistrategy Citadel ($900 million); Larry Robbins of stock and credit-focused Glenview Capital Management; and Leon Cooperman of stock picker Omega Advisors.
"Whatever I make will be returned to society to help create a better world for all and a world of equal opportunity," Cooperman said by email when asked about the report.
Like Dalio, Cooperman has signed the Giving Pledge, a commitment to dedicate most of his wealth to philanthropy. Others, including Soros and Griffin, have given large sums to charity.
(Read more: Hedge fund manager Griffin to donate to Harvard)
Spokesmen for Bridgewater, Glenview, Paulson, SAC, Renaissance and Citadel declined to comment. Other representatives did not respond to a request.
The list comes the day after the prospect of higher taxes on fund profits was again raised in Congress.
Rep. Dave Camp, the Republican chairman of the House Committee on Ways and Means, wrote in The Wall Street Journal on Tuesday that he would seek to close what some see as a tax loophole for private fund managers.
"We can clean up provisions like 'carried interest' that allow certain private-equity firms to get the investment-income tax rate on what anyone else would call normal wage income," Camp wrote.
Washington has long sought to change the treatment of capital gains—investments held more than a year are taxed at just 20 percent—but the efforts have largely failed.
Critics say the provision is unfair, because the pay is derived from investment performance rather than an annual salary or bonus, which would be taxed at nearly 40 percent. Hedge fund managers at firms that trade frequently are little affected by the law.
The Managed Funds Association, the top hedge fund lobbyist in Washington, did not release a statement about the Camp proposal and did not immediately respond to a request for comment. The group has previously sought to protect the tax treatment.
(Read more: Inside hedge fund pay: $10M for a 10 percent return)
The private equity industry released this critique of Camp:
"Last year, private equity invested over $400 billion dollars in thousands of businesses of all shapes and sizes across all 435 congressional districts. This is why it is so disappointing that Chairman Camp chose to single out private equity, real estate, and venture capital investment by exacting a 40 percent tax increase that will discourage new investment," Steve Judge, president and CEO of the Private Equity Growth Capital Council, said in a statement.
(Read more: He's back: The best hedge fund of 2013)
—By CNBC's Lawrence Delevingne. Follow him on Twitter