The Wishart Autoregressive (WAR) process is a dynamic model for time series of multivariate stochastic volatility. The WAR naturally accommodates the positivity and symmetry of volatility matrices and provides closed-form non-linear forecasts. The estimation of the WAR is straighforward, as it...

The Wishart Autoregressive (WAR) process is a multivariate process of stochastic positive definite matrices. The WAR is proposed in this paper as a dynamic model for stochastic volatility matrices. It yields simple nonlinear forecasts at any horizon and has factor representation, which separates...

This article uses a bivariate stochastic volatility model to examine the leverage effects for two stock returns. The results show that the leverage effect estimates for each stock depend on the degree to which the risk premium is affected by the information about the other stock and that...

We develop a unified approach with closed-form solutions for pricing bonds, stocks, currencies and their derivatives. The specification assumes a fundamental risk factor represented by a stochastic positive definite matrix following a Wishart autoregressive (WAR) process. By assuming a...

Dai, Singleton (2000) introduced a typology of affine diffusion models when the domain ofadmissible values of the factors is an intersection of half planes and under some additional constraintson the parameters. This condition on the domain and the additional sufficient constraintsare...

We develop a unified approach with closed-form solutions for pricing bonds, stocks,currencies and their derivatives. The specification assumes a fundamental risk factorrepresented by a stochastic positive definite matrix following a Wishart autoregressive(WAR) process. By assuming a...

This paper extends to the multiasset framework the closed-form solution for options withstochastic volatility derived in Heston (1993) and Ball and Roma (1994). This extensionintroduces a risk premium in the return equation and considers Wishart dynamics for theprocess of the stochastic...

This paper reveals that the class of Affine Term Structure Models (ATSMs) introduced by Duffie and Kan (1996) is larger than previously considered in the literature. In the framework of risk factors following a Wishart autoregressive process, we define the Wishart Term Structure Model (WTSM) as...