We propose a dynamic asset-market equilibrium model in which (1) an "innovative" asset with as-yet-unknown average payoff is traded, and (2) investors delegate investment to experts. Experts secretly renege on investors' orders and take on leveraged positions in the asset to manipulate...

Across numerous asset classes, momentum strategies have historically generated high Sharpe ratios and strong positive alphas relative to standard asset pricing models. However, the returns to momentum strategies are negatively skewed: they experience infrequent but strong and persistent strings...