Hedge fund managers receive performance fees proportional to their funds' profits, plus regular fees proportional to assets. Managers with constant relative risk aversion, constant investment opportunities, maximizing utility of fees at long horizons, choose constant Merton portfolios. The effective risk aversion depends on performance fees, which shrink the true risk aversion towards one. Thus, performance fees have ambiguous risk-shifting implications, depending on managers' own risk aversion. Further, managers behave like investors acting on their own behalf, but facing drawdown constraints. A Stackelberg equilibrium between investors and managers trades off the costs of performance fees, with their potential to align preferences. Only aggressive investors voluntarily pay high performance fees, and only if managers are even more aggressive.