This paper tests whether the "disposition effect," that is the tendency of investors to ride losses and realize gains, induces "underreaction" to news, leading to return predictability. I use data on mutual fund holdings to construct a new measure of reference purchasing prices for individual...

This paper uses social networks to identify information transfer in security markets. We focus on connections between mutual fund managers and corporate board members via shared education networks. We find that portfolio managers place larger bets on connected firms and perform significantly...

On average, stock prices rise around scheduled earnings announcement dates. We show that this earnings announcement premium is large, robust, and strongly related to the fact that volume surges around announcement dates. Stocks with high past announcement period volume earn the highest...

We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically...

We present a model in which some investors are prohibited from using leverage and other investors' leverage is limited by margin requirements. The former investors bid up high-beta assets while the latter agents trade to profit from this, but must de-lever when they hit their margin constraints....

We study the impact of social networks on agents' ability to gather superior information about firms. Exploiting novel data on the educational background of sell-side analysts and senior corporate officers, we find that analysts outperform by up to 6.60% per year on their stock recommendations...

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...

We study the impact of social networks on agents' ability to gather superior information about firms. Exploiting novel data on the educational backgrounds of sell side equity analysts and senior officers of firms, we test the hypothesis that analysts' school ties to senior officers impart...