This paper demonstrates that liquidity risk as measured by the covariation of fund returns with unexpected changes in aggregate liquidity is an important predictor of hedge-fund performance. The results show that funds that significantly load on liquidity risk subsequently outperform low-loading funds by about 6.5% annually, on average, over the period 1994−2009, while negative performance is observed during liquidity crises. The returns are independent of share restriction, pointing to a possible imbalance between the liquidity a fund offers its investors and the liquidity of its underlying positions. Liquidity risk seems to account for a substantial part of hedge-fund performance. The results suggest several practical implications for risk management and manager selection.