Multinationals and stock return comovement

We find that when a U.S. domestic firm becomes a multinational (MNC), its returns comove more with those of existing multinational firms and less with those of purely domestic firms in the following year. This result is robust to a propensity score matching method and an exogenous shock. Turnover comovement and changes in mutual funds' holdings of these MNC initiators further indicate that investors prefer multinationals as a style investment. Moreover, MNC initiators with larger foreign sales experience larger shifts in return comovement. Finally, the effect of MNC initiation on return comovement is relatively weaker for 2000–2016 than for 1979–1997.