Momentum and Mean-Reversion in Strategic Asset Allocation
We study a dynamic asset allocation problem in which stock returns exhibit short-run momentum and long-run mean reversion. We develop a tractable continuous-time model that captures these two predictability features and derive the optimal investment strategy in closed-form. The model predicts negative hedging demands for medium-term investors, and an allocation to stocks that is non-monotonic in the investor's horizon. Momentum substantially increases the economic value of hedging time-variation in investment opportunities. These utility gains are preserved when we impose realistic borrowing and short-sales constraints and allow the investor to trade on a monthly frequency.