Suppose a fund manager uses predictors in changing port-folio allocations over time. How does predictability translate into portfolio decisions? To answer this question we derive a new model within the Bayesian framework, where managers are assumed to modulate the systematic risk in part by...

Short sellers are perceived as informed, sophisticated investors. Yet little is known about their actual performance and trading strategies. Using a novel, hand-collected data set of daily position disclosures in Europe, we identify the entry, change, and exit dates of large short-sale positions...