An Institutional Theory of Momentum and Reversal
We propose a rational theory of momentum and reversal based on delegated portfolio management. An investor can hold assets through an index or an active fund. Investing in the active fund involves a time-varying cost, interpreted as managerial perk or ability. The investor responds to an increase in the cost by flowing out of the active and into the index fund. While prices of assets held by the active fund drop in anticipation of these outflows, the drop is expected to continue, leading to momentum. Because outflows push prices below fundamental values, expected returns eventually rise, leading to reversal. Besides momentum and reversal, fund flows generate comovement, lead-lag effects and amplification, with all effects being larger for assets with high idiosyncratic risk. The active-fund manager's concern with commercial risk makes prices more volatile.
-
-
Copy CitationDimitri Vayanos and Paul Woolley, "An Institutional Theory of Momentum and Reversal," NBER Working Paper 14523 (2008), https://doi.org/10.3386/w14523.Download Citation
-
Published Versions
Dimitri Vayanos & Paul Woolley, 2013. "An Institutional Theory of Momentum and Reversal," Review of Financial Studies, Society for Financial Studies, vol. 26(5), pages 1087-1145. citation courtesy of 
Related
More from the NBER
In addition to working papers, the NBER disseminates affiliates’ latest findings through a range of free periodicals—the NBER Reporter, the NBER Digest, the Bulletin on Health, the Bulletin on the Economics of Alzheimer's, and the Bulletin on Entrepreneurship—as well as research spotlights, lectures, and panel videos.
