We introduce a decomposition showing precisely how actively-managed portfolio returns can be separated into three measurable components that we call Opportunity, Foresight, and Active Management Risk. Opportunity reflects the degree to which the investment opportunity set contains exploitable...

This paper combines the use of portfolio holdings data and conditioning information to create a new performance measure. Our conditional weight-based measure has several advantages. Using conditioning information avoids biases in weight-based measures as discussed by Grinblatt and Titman (1993)....