The ABCs of Hedge Funds: Alphas, Betas, & Costs
Despite the retrenchment of the hedge fund industry in 2008, hedge fund assets under management are currently over one and a half trillion dollars. We analyze the potential biases in reported hedge fund returns, in particular survivor-ship bias and back fill bias. We then decompose the returns into three components: the systematic market exposure (beta), the value added by hedge funds (alpha), and the hedge fund fees (costs). We analyze the performance of a universe of about 8,400 hedge funds from the TASS database from January 1995 through December 2009. Our results indicate that both survivor-ship and back fill biases are potentially serious problems. Adjusting for these biases brings the net return from 14.26% to 7.63% for the equally weighted sample. Over the entire period, this return is slightly lower than the S&P 500 return of 8.04%, but includes a statistically significant positive alpha. We estimate a pre-fee return of 11.42%, which we split into a fee (3.78%), an alpha (3.01%), and a beta return (4.62%). The positive alpha is quite remarkable, since the mutual fund industry in aggregate does not produce alpha net of fees. The year by year results also show that alphas from hedge funds were positive during every year of the last decade, even through the recent financial crisis of 2008 and 2009.
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