One-Month Individual Stock Return Reversals and Industry Return Momentum

Abstract

There is a large stream of literature that documents one-month return reversal patterns for individual stocks. Some studies term this reversal pattern overreaction, while others simply skip one-month returns in order to examine longer term momentum patterns in stocks. At the same time, the literature documents that momentum patterns in stock returns tend to be related to momentum patterns in returns to industry portfolios. Further, industry portfolios tend to exhibit return momentum, even at one-month horizons. This paper examines the relationship between individual stock return reversals and industry momentum. We find that individual stock return reversals tend to be related to return reversions within industries. Thus, the predictions of the overreaction hypothesis do not hold, market-wide, but rather within industries. This leads to a dramatically different trading strategy than those suggested by either the overreaction hypothesis or by industry momentum. That is, a strategy that buys the losers within the previous month’s winning industry and shorts the winners in the previous month’s losing industry significantly outperforms an overreaction-based strategy that simply buys losers and shorts winners in the market overall, and it outperforms a industry-momentum-based strategy that simply buys the previous month’s winning industry portfolio and shorts the previous month’s losing industry portfolio.