The paper features an analysis of causal relations between the VIX, S&P500, and the realised volatility (RV) of the S&P500 sampled at 5 minute intervals, plus the application of an Artificial Neural Network (ANN) model to forecast the VIX. Causal relations are analysed using the recently...

For the major foreign exchange rates, it is found that the optimal modelling frequency of volatility is weekly for forecast horizons ranging from 1 week up to 1 month. Autoregressive modelling is based on realized volatility measures computed from 30 min returns