There is much evidence in the literature that the volatilities of equity returns show evidence of asymmetric responses to good and bad news. At the same time, there is evidence that the unconditional distribution of stock returns is asymmetric as well. This paper examines the effects of...

Many popular techniques for determining a securities firm's value-at-risk are based upon the calculation of the historical volatility of returns to the assets that comprise the portfolio and of the correlations between them. One such approach is the JP Morgan RiskMetrics methodology using...

The development of multivariate generalized autoregressive conditionally heteroscedastic (MGARCH) models from the original univariate specifications represented a major step forward in the modelling of time series. MGARCH models permit time-varying conditional covariances as well as variances,...