[We study an equilibrium model with restricted investor participation in which strategic arbitrageurs reap profits by exploiting mispricings across different market segments. We endogenize the asset structure as the outcome of a security design game played by the arbitrageurs. The equilibrium asset structure depends realistically upon considerations such as depth and gains from trade. It is neither complete nor socially optimal in general; the degree of inefficiency depends upon the heterogeneity of investors.]

Many financial applications, such as risk analysis, and derivatives pricing, depend on time scaling of risk. A common method for this purpose is the square-root-of-time rule where an estimated quantile of a return distribution is scaled to a lower frequency by the square root of the time horizon. This paper examines time scaling of quantiles when returns follow a jump diffusion process. We demonstrate that when jumps represent losses, the square-root-of-time rule leads to a systematic underestimation of risk, whereby the degree of underestimation worsens with the time horizon, the jump intensity and the confidence level.

We study an equilibrium model with restricted investor participation in which strategic arbitrageurs reap profits by exploiting mispricings across different market segments. We endogenize the asset structure as the outcome of a security design game played by the arbitrageurs. The equilibrium asset structure depends realistically upon considerations such as depth and gains from trade. It is neither complete nor socially optimal in general; the degree of inefficiency depends upon the heterogeneity of investors. The Author 2008. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please email: [email protected], Oxford University Press.

There are increasing calls for the regulation of hedge funds, both for consumer protection and systemic reasons. We argue that the consumer protection arguments for direct regulation are not convincing, but find that the systemic concerns are sufficiently serious to warrant some forms of regulation. Existing regulatory methods, disclosure and activity restrictions, are unsuitable for hedge funds. Any future regulation must reduce the likelihood and potential costs of the failure of systemically important hedge funds while at the same time preserving the wider market benefits of hedge funds’ ongoing activities.

Most financial risk regulations assume that asset returns are exogenous, where risk is estimated from historical data. This assumption fails to take into account the feedback effect of trading decisions on prices. We investigate the consequences of risk constrained trading by means of simulations of a general equilibrium model with a value-at-risk constraint and compare the results to the case when risk constraints are not present. Prices are lower on average in the presence of risk regulation, while volatility is higher. Risk regulation may have the perverse effect of exacerbating price fluctuations.