We investigate financial markets under model risk caused by uncertain volatilities. For this purpose we consider a financial market that features volatility uncertainty. To have a mathematical consistent framework we use the notion of G-expectation and its corresponding G-Brownian motion...

This paper documents the fact that in options markets, the (percentage) implied volatility bid-ask spread increases at an increasing rate as the option's maturity date approaches. To explain this stylized fact, this paper provides a market microstructure model for the bid-ask spread in options...

Fixed income Asian options are frequently adopted by companies to hedge interest rate risk. Having a payoff structure depending on the cumulative short-term rate makes them particularly informativeabout interest rate volatility risk. Based on a joint dataset of bonds and Asian interest rate...

We propose a model of price formation in which the trading price varies only if the value of the information signal is large enough to guarantee a profit in excess of transaction costs. Using transaction data only, we extract: (i) the conditional volatility of the underlying security, which is...

In a production economy with trade in financial markets motivated by the desire to share labor-income risk and to speculate, we show that speculation increases volatility of asset returns and investment growth, increases the equity risk premium, and reduces welfare. Regulatory measures, such as...

Compared to the predictions of complete market models, actual exchange rates are puzzlingly smooth and only weakly correlated with macro-economic fundamentals, suggesting that market incompleteness plays a key role in exchange rate dynamics. Incompleteness in international financial markets...

We introduce convenience yields on dollar bonds into an incomplete-market equilibrium model of exchange rates and interest rates. The convenience yield enters as a stochastic wedge in the Euler equation for exchange rate determination. The model identifies a novel safe-asset convenience yield...

During the last two decades, the degree of openness of national financial systems has increased substantially. At the same time, asymmetries in information and other financial market frictions have remain prevalent. We study both empirically and theoretically the implications of the opening up...

We study the existence of equilibria with endogenously complete markets in a continuous-time, heterogenous agents economy driven by a multidimensional diffusion process. Our main results show that if prices are real analytic as functions of time and the state variables of the model then a...