Hedge Funds

Betting Against Beta

Topics - Hedge Funds Factor/Style Investing Defensive

${ numberSection } ${ text }
Betting Against Beta

A basic premise of the capital asset pricing model (CAPM) is that all agents invest in the portfolio with the highest Sharpe ratio, or expected excess return per unit of risk, and leverage or de-leverage this portfolio to suit their risk preferences.

However, many investors — such as individuals, pension funds and mutual funds — are constrained in the leverage that they can take, and therefore overweight risky securities instead. This behavior of tilting toward beta suggests high-beta assets require lower risk-adjusted returns than low-beta assets. Indeed, the security market line for U.S. stocks is too flat relative to the CAPM and is better explained by the CAPM with limited borrowing.

This raises several questions: What is the magnitude of this anomaly relative to the size, value and momentum effects? Is betting against beta rewarded in other countries and asset classes? How does the return premium vary over time and in the cross section? How does one bet against beta?

We address these questions by considering a dynamic model of leverage constraints and by presenting consistent empirical evidence from stock, bond, credit and futures markets in 20 countries. (We found relative flatness in 18 of 19 international equity markets, in many asset classes.)

We show how this deviation from the standard CAPM can be captured using betting-against-beta factors. The return of the BAB factor rivals those of all the standard asset-pricing factors — value, momentum and size — in terms of economic magnitude, statistical significance, and robustness across time periods, sub-samples of stocks and global asset classes.

Fama/DFA Prize First Place 2015

Swiss Finance Institute Outstanding Paper Award 2011

Roger F. Murray Prize Third Place 2011

Published In

Journal of Financial Economics

AQR Capital Management, LLC, (“AQR”) provide links to third-party websites only as a convenience, and the inclusion of such links does not imply any endorsement, approval, investigation, verification or monitoring by us of any content or information contained within or accessible from the linked sites. If you choose to visit the linked sites, you do so at your own risk, and you will be subject to such sites' terms of use and privacy policies, over which AQR.com has no control. In no event will AQR be responsible for any information or content within the linked sites or your use of the linked sites.

The information contained herein is only as current as of the date indicated, and may be superseded by subsequent market events or for other reasons. The views and opinions expressed herein are those of the author and do not necessarily reflect the views of AQR Capital Management, LLC, its affiliates or its employees. This information is not intended to, and does not relate specifically to any investment strategy or product that AQR offers. It is being provided merely to provide a framework to assist in the implementation of an investor’s own analysis and an investor’s own view on the topic discussed herein. Past performance is not a guarantee of future results.


Hypothetical performance results have many inherent limitations, some of which, but not all, are described herein. The hypothetical performance shown was derived from the retroactive application of a model developed with the benefit of hindsight.  Hypothetical performance results are presented for illustrative purposes only.


Diversification does not eliminate the risk of experiencing investment loss.


Certain publications may have been written prior to the author being an employee of AQR.

This material is intended for informational purposes only and should not be construed as legal or tax advice, nor is it intended to replace the advice of a qualified attorney or tax advisor.


AQR Capital Management is a global investment management firm, which may or may not apply similar investment techniques or methods of analysis as described herein. The views expressed here are those of the authors and not necessarily those of AQR.