Conditional risk

We study the extent to which time-variation in market betas influence estimates of CAPM alphas. Given the observed variation in conditional market betas, market risk premia, and market variance, the required compensation for conditional market risk can, in theory, be as large as the unconditional equity premium. We implement the conditional CAPM using state-of-the-art methods in a broad global sample. We find that accounting for conditional risk helps explain the return on all the major anomalies we consider and that conditional risk explains two percentage points of alpha for value, investment, and momentum strategies in recent years.