The hedge fund industry isn't dead but it struggled overall

2018 was a rough year for hedge funds with the average one losing 6.7%, according to the HFRX Global Hedge Fund Index. That compares to -4.4% for the S&P 500.

However one of the greatest hedge fund bucked the trend as Bridgewater's flagship Pure Alpha Strategy gained 14.6%.

Dalio had publicized shorts on Italian banks and bonds that potentially did very well but there's no indication on what contributed to the win. Bridgewater highlights its use of algorithms, an ultra-transparent and sometimes harsh culture, and its massive capital base.

Ray Dalio founded the firm but has stepped back in recent years and its current chief executive officers are David McCormick and Eileen Murray.

Dalio is working on a book on investing that's sure to be a hit.

Separately, fellow mammoth hedge fund Renaissance Technologies returned 8.5% in its Institutional equities Fund while its Intuitional Diversified Global Equities Fund gained 10.3%. There's no word yet on the flagship Medallion Fund, which has made annualized gains of around 70% for 25 years (put that into a compound interest calculator and blow your mind).

Meanwhile, David Einhorn's Greenlight lost 34%, Dan Loeb's Third Point fell 11% and Bill Ackman's Pershing Square declined 0.7%.