In a year when hedge funds saw bad performance and a surge in shutdowns, a few firms managed to avoid the carnage. The world's biggest hedge fund, the $160 billion Bridgewater Associates, was one of them. Bridgewater's flagship fund, Pure Alpha, posted a 14.6% return net of fees in 2018, according to a person familiar with the firm's performance. That made the fund one of only a few to post big gains in a year when hedge funds on average were down about 6.7%, according to the HFRX Global Hedge Fund Index.