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...

Utilizing a novel style identification procedure, we show that style-shifting is a dynamic strategy commonly employed by hedge fund managers. Three quarters of hedge funds shifted their investment styles at least once over the period from January 1994 to December 2013. We perform empirical tests...