Global style momentum

We first document the empirical regularity of significant style-level momentum returns in international data. Then we test some Barberis and Shleifer (2003) propositions regarding style momentum. One proposition holds that Sharpe ratios from style-level momentum strategies should be at least as large as stock-level momentum Sharpe ratios. We test for style-level momentum profitability in our sample of global markets and find some evidence of larger style momentum Sharpe ratios, especially within the value-growth style. However, most of the evidence favors stock momentum. The Barberis and Shleifer (2003) model also suggests that style momentum could be time-varying. Variables that effectively condition stock momentum are much less effective with style momentum.