On Evidence and Sources of International Momentum: an Empirical Study

Momentum investment strategy which buys past intermediate-term winner stocks and sells past intermediate-term loser stocks generates positive profits over three-month to one-year holding periods. This price anomaly has attracted a lot of attention since it is inconsistent with the traditional Market-Efficiency Hypothesis. This book uses an extensive international data set first to detect the existence of international momentum effect, then to investigate the sources of momentum profits. With a sample of about 20,000 stocks from 18 developed countries during 1973-2001, we find that an internationally diversified momentum strategy earns significant positive profits over intermediate horizons. On the sources of momentum profits, our findings suggest that momentum phenomenon is linked to information dissemination mechanism among investors, which is consistent with the prediction of existing behavioral theories. Our results also indicate that investing style is not an independent source of momentum. The analysis should be useful for academicians who are interested in testing market efficiency hypothesis, and may also serve as a reference for investment professionals.