It is well known that information arrival has an impact on prices volatility, and trading volume in financial markets (see e.g., Goodhart and O'Hara 1997). Scheduled macroeconomic announcements, such as monthly employment figures, consumer prices, or building permits, stand out from the steady...

This paper delineates the simultaneous impact of non-anticipated information on first and second moments of the intraday price process by including appropriate variables accounting for the news flow into both the mean and the variance function. This allows us to differentiate between the...