We present evidence that equity momentum strategies are partially driven by positive-feedback trading intermediated via the mutual fund sector. We identify a U.S.-specific structural break to this channel that substantially weakened the relationship between fund flows and past style returns. As...

We show that mutual fund ratings generate correlated demand that creates systematic price fluctuations. Mutual fund investors chase fund performance via Morningstar ratings. Until June 2002, funds pursuing the same investment style had highly correlated ratings. Therefore, rating-chasing...

We show that a June 2002 reform in Morningstar's mutual fund rating methodology led to substantial drop in the profitability of momentum-related asset pricing factors. Before the reform, funds pursuing the same investment style had correlated ratings heavily influenced by recent style...