The hedge fund mirage vindicated: good for managers, but bad for investors
What Lack does is try to track the fate of the typical dollar invested in a hedge fund. He finds that the returns have been dismal. In response, AIMA says we should look instead at the fate of the typical fund rather than weighting the funds by dollars.
AIMA is an association of fund managers, and as a vindication of fund managers qua people this works fine. Hedge funds became famous and lucrative because a lot of hedge fund managers really did get some very good returns. But this precisely speaks to Lack's point. When hedge funds, as an asset class, were small and relatively obscure they did quite well. That made them bigger and less obscure, but they haven't done well since then. Everyone knows that one of the worst foibles of retail investors is a tendency to chase growth. After, tech stocks appreciate a lot people think to themselves "I should get into high-tech." Then when the market crashes, they think "man stocks are risky, I want to get into something safer." This kind of buy high, sell low trading leads to big losses but it appeals to people's herd instincts. Lack is basically saying that hedge funds as an asset class are just another example of this. The time to get into hedge funds was back when nobody was doing it. Then they did well, and everyone rushed into hedge funds after the gains had already been made. AIMA doesn't rebut this at all. Instead they're basically saying "don't blame us, investors should have gotten in earlier."