The world's biggest hedge funds are getting bigger and at a faster rate than their smaller rivals, according to a new report.

Alpha Magazine's annual survey of hedge fund assets shows that the top 100 hedge funds in the world now manage more than $1 trillion combined, accounting for 68% of all hedge fund assets. Prior to asset growth of 39% last year, the top 100 held 65% of all assets.

The magazine says that in the summer of 2001, Barton Biggs captured the attention of hedge fund managers when he announced to the world that their industry was in the midst of a bubble. Morgan Stanley's chief market strategist at the time, Biggs likened investments flowing into hedge funds, which then managed a collective $500 billion, to a gold rush and warned that sizable blowups were imminent.