The sum of squared intraday returns provides an unbiased and almost error-free measure of ex-post volatility. In this … paper we develop a nonlinear Autoregressive Fractionally Integrated Moving Average (ARFIMA) model for realized volatility …, which accommodates level shifts, day-of-the-week effects, leverage effects and volatility level effects. Applying the model …

average daily returns, even though the volatility is virtually unchanged when the frequency is lower. The volatility from the … highest to the lowest frequency is about 30% lower as compared with the buy-and-hold strategy volatility, but the average … returns approach the buy-and-hold returns when frequency is lower. The 30% reduction in volatility appears if we invest …