This paper deals with the main theoretical problems regarding the application of stochastic processes to leptokurtic financial return distributions. A sort of statistical tests based on the stock index Banamex 30 is performed in order to choose the stochastic model that provide the best fit to...

A new multivariate time series model with various attractive properties is motivated and studied. By extending the CCC model in several ways, it allows for all the primary stylized facts of financial asset returns, including volatility clustering, non-normality (excess kurtosis and asymmetry),...

Both unconditional mixed-normal distributions and GARCH models with fat-tailed conditional distributions have been employed for modeling financial return data. We consider a mixed-normal distribution coupled with a GARCH-type structure which allows for conditional variance in each of the...