← Search

Review of Financial Studies Vol. 15 No. 2 2002

Momentum and Autocorrelation in Stock Returns

Jonathan Lewellen

Abstract

This article studies momentum in stock returns, focusing on the role of industry, size, and book-to-market (B/M) factors. Size and B/M portfolios exhibit momentum as strong as that in individual stocks and industries. The size and B/M portfolios are well diversified, so momentum cannot be attributed to firm- or industry-specific returns. Further, industry, size, and B/M portfolios are negatively autocorrelated and cross-serially correlated over intermediate horizons. The evidence suggests that stocks covary "too strongly" with each other. I argue that excess covariance, not underreaction, explains momentum in the portfolios.

Volume
15
Issue
2
Pages
533-563
Sources
bibtex:phds-export.bib

Cite