Market States and Momentum

We test overreaction theories of short-run momentum and long-run reversal in the cross section of stock returns. Momentum profits depend on the state of the market, as predicted. From 1929 to 1995, the mean monthly momentum profit following positive market returns is 0.93%, whereas the mean profit following negative market returns is −0.37%. The up-market momentum reverses in the long-run. Our results are robust to the conditioning information in macroeconomic factors. Moreover, we find that macroeconomic factors are unable to explain momentum profits after simple methodological adjustments to take account of microstructure concerns. SEVERAL BEHAVIORAL THEORIES have been developed to jointly explain the shortrun cross-sectional momentum in stock returns documented by Jegadeesh and Titman (1993) and the long-run cross-sectional reversal in stock returns documented by DeBondt and Thaler (1985). 1 Daniel, Hirshleifer, and Subrahmanyam (1998; hereafter DHS) and Hong and Stein (1999; hereafter HS) each employ different behavioral or cognitive biases to explain these anomalies. 2, 3