I estimated ARIMA model with daily gold time series. The residuals' corelogram is flat but its squared is not flat. Already I tried eVİEWS heterodasticity >> arch effect and ı found prob value 0.00 so there is heterodasticity. Can ı continue with ARIMA? (Flat correlogram is residuals other is squared residuals)(Are there permission to continue with ARIMA in this case?)