Hi useRs, a daily garch(1,1) model can be extended whereby the variance equation incorporates say higher frequency volatility measure. The variance equation would look something like: s(t)2 = garch(1,1) + a*v(t-1) whereby v(t-1) would be the intraday vola of yesterday ("a" the coef.). How can this be implemented in R? I checked "garch" of "tseries". An extended formula cannot be specified. fitGarch of "fseries" might be able to do that. Unfortunately, I am not quite sure how to specify in the fseries package. Or would the estimation have do be done manually? Comments and hints highly appreciated! Thanks! Bernd [[alternative HTML version deleted]]