The Moving Average Ratio and Momentum

I show the ratio of the short‐term moving average to the long‐term moving average (moving average ratio, MAR) has significant predictive power for future returns. The MAR combined with nearness to the 52‐week high explains most of the intermediate‐term momentum profits. This suggests that an anchoring bias, in which investors use moving averages or the 52‐week high as reference points for estimating fundamental values, is the primary source of momentum effects. Momentum caused by the anchoring bias do not disappear in the long‐run even when there are return reversals, confirming that intermediate‐term momentum and long‐term reversals are separate phenomena.