Existing literature documents that cross-sectional stock returns exhibit both price momentum and earnings momentum. In this paper, we examine whether commonly used style and sector indexes also have momentum patterns. We show that style indexes exhibit strong price momentum, but little evidence...

We argue that active fund managers can pick stocks only when the market presents such opportunities. We propose measures of stock selection opportunity and show evidence that a significant portion of mutual funds time stock selection, i.e., trading more when stock selection opportunities are...