We investigate the idea that stock-market participation is influenced by social interaction. We build a simple model in which any given 'social' investor finds it more attractive to invest in the market when the participation rate among his peers is higher. The model predicts higher...

We develop a theory of stock-market crashes based on differences of opinion among investors. Because of short-sales constraints, bearish investors do not initially participate in the market and their information is not revealed in prices. However, if other, previously-bullish investors have a...

A number of theories have been proposed to explain the medium-term momentum in stock returns identified by Jegadeesh and Titman (1993). We test one such theory--based on the gradual-information-diffusion model of Hong and Stein (1997)--and establish three key results. First, once one moves past...

Standard models of informed speculation suggest that traders try to learn information that others do not have. This result implicitly relies on the assumption that speculators have long horizons, i.e, can hold the asset forever. By contrast, we show that if speculators have short horizons, they...

We build a model that helps explain why increases in liquidity - such as lower bid-ask spreads, a lower price impact of trade, or higher share turnover - predict lower subsequent returns in both firm-level and aggregate data. The model features a class of irrational investors, who underreact to...

We develop a model of stock prices in which there are both differences of opinion among investors as well as short-sales constraints. The key insight that emerges is that breadth of ownership is a valuation indicator. When breadth is low i.e., when few investors have long positions in the stock...

We assume that the instantaneous riskless rate reverts towards a central tendency which in turn, is changing stochastically over time. As a result, current short-term rates are not" sufficient to predict future short-term rates movements, as would be the case if the central" tendency was...