Rich get richer as big hedge funds rake in cash

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Despite critics saying hedge funds have seen better days—and returns—investors are still buying in.

The largest hedge fund firms in the Americas—those managing $1 billion or more in assets—kept adding assets in the first half of the year, according to Absolute Return's twice-annual Billion Dollar Club ranking.

That puts assets for the 287-firm group at $1.57 trillion as of July 1, up 7.46 percent from $1.46 trillion at the start of 2013 and near the all-time-high of $1.68 trillion in July 2008. Nineteen new hedge funds firms joined the club with assets hitting $1 billion or more since January.

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Pensions, endowments and other investors are adding to the $2.7 trillion hedge fund industry despite mediocre performance so far this year, at least compared to stocks.

The Absolute Return Composite Index, which tracks thousands of funds across various strategies, gained just 4.05 percent through July. That compares to gains of 19.63 percent for the S&P 500 index and 14.14 percent for the MSCI World Index over the same period.

Bridgewater Associates remains the largest firm in the Americas at $81.9 billion in hedge fund assets (Ray Dalio's macro shop manages $150 billion overall).

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That leading position is despite a $1.4 billion drop from January—the firm's first six-month drop in assets since 2009—due to slightly negative performance in its flagship Bridgewater Pure Alpha Trading Co. fund.

It fell 0.89 percent net of fees through June, although the fund is back up 2.8 percent through August, according to a person familiar with the returns.

Others in the top five of hedge fund assets were multistrategy shops J. P. Morgan Asset Management ($50.6 billion), Och-Ziff Capital Management Group ($33.9 billion) and BlackRock ($28.7 billion). Value investor Baupost Group was fifth at $28.5 billion.

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The largest gainers so far this year were J.P. Morgan (up $6.6 billion); equity-focused Adage Capital Management (up $4 billion to $22 billion); and quantitative shop AQR Capital Management (up $3.9 billion to $24.2 billion).

The largest losers were multistrategy First Quadrant (down $1.1 billion to $11.1 billion); multi-strategy Citi-spinout Napier Park Global Capital (down $1.87 billion to $2.83 billion); and equity firm Standard Pacific (down more than $1 billion to $1.5 billion).

—By CNBC's Lawrence Delevingne. Follow him on Twitter @ldelevingne.