In recent years, non-Gaussian time series have begun to receive considerable attention and forecasting methods are slowly being developed. Oneparticular area of non-Gaussian time series that has important applications is time series taking positive values only. Two important areas in finance in which these arise are realized volatility and the duration between transactions. Important contributions to date have been Engle and Russell’s (1998) bautoregressive conditional durationQ model and Andersen, Bollerslev, Diebold, and Labys (2003). Because of the importance
of these applications, we expect much more work in this area in the next few years.