Do Style Momentum Strategies Produce Abnormal Returns: Evidence From Index Investing

In this study, we investigate the return enhancement ability of style momentum strategy: a strategy that switches between value and growth styles based on previous performance. We explore the variation in abnormal returns of long-only and long-short momentum strategies using various style based indexes (Russell value/growth indexes, Fama-French value/growth indexes, and MSCI value/growth indexes) where value and growth stocks are classified using different criteria. Our results show that the performance of style momentum does vary across different index families. We first find that in general the long-only strategies create significant positive abnormal returns whereas the long-short strategies do not. Second, for a fixed formation period, abnormal returns of the strategies tend to decrease when the length of holding periods increase. Third, abnormal returns are stronger and more significant when rotating within large cap value and growth indexes while abnormal returns are weaker and inconsistent when rotating within small cap value and growth indexes. Fourth, strategies based on rotating across all market cap levels do not generate consistently significant positive abnormal returns for Russell indexes or Fama-French indexes but they do for MSCI indexes. Fifth, individual stock momentum only explains a very small portion of the returns of style moment strategies