2. Advantages of Log Returns: - Log returns can be easily aggregated across time, unlike simple returns. - Log returns are symmetric around 0 and can range from minus infinity to plus infinity, providing a wider range of possible values compared to simple returns.
3. Realized Volatility: - Realized volatility measures the magnitude of daily price movements, regardless of direction, over a specific period. - It is calculated as the daily standard deviation of log returns of an underlying asset, index, instrument, security, or ETF with an assumed mean of zero.
4. Realized Variance: - Andersen and Bollerslev introduced the concept of realized variance, an ex-post observable measure based on the sum of squared intra-day returns. - This measure provides further insights into the volatility of financial assets.