Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to...

Stocks with large increases in call implied volatilities over the previous month tend to have high future returns while stocks with large increases in put implied volatilities over the previous month tend to have low future returns. Sorting stocks ranked into decile portfolios by past call...

This paper makes indirect inference about the time-variation in expected stock returns by comparing unconditional sample variances to estimates of expected conditional variances. The evidence reveals more predictability as more information is used, and no evidence that predictability has...

Real investors and markets are too complicated to be neatly summarized by a few selected biases and trading frictions. The "top down" approach to behavioral finance focuses on the measurement of reduced form, aggregate sentiment and traces its effects to stock returns. It builds on the two...

The hypothesis that financial markets punish traders who make relatively inaccurate forecasts and eventually eliminate the effect of their beliefs on prices is of fundamental importance to the standard modeling paradigm in asset pricing. We establish necessary and sufficient conditions for...

Financial markets have become increasingly global in recent decades, yet the pricing of internationally traded assets continues to depend strongly upon local risk factors, leading to several observations that are difficult to explain with standard frameworks. Equity returns depend upon both...

Despite a large and growing theoretical literature on flights to safety, there does not appear to exist an empirical characterization of flight-to-safety (FTS) episodes. Using only data on bond and stock returns, we identify and characterize flight to safety episodes for 23 countries. On...

A key result of the Capital Asset Pricing Model (CAPM) is that the market portfolio---the portfolio of all assets in which each asset's weight is proportional to its total market capitalization---lies on the mean-variance efficient frontier, the set of portfolios having mean-variance...