The information content of implied volatilities and intra-day returns is compared, in the context of forecasting index volatility over horizons from one to twenty days. Forecasts of two measures of realised volatility are obtained after estimating ARCH models using daily index returns, daily...

The volatility process of the Samp;P 100 index and all its constituent stocks are compared after estimating ARCH models from ten years of daily returns, from 1983 to 1992. The leverage effect of Black (1976) is estimated from an extension of the asymmetric volatility model of Glosten et al...