effects of highs and lows on a stock's beta and return volatility. We find that implied volatilities and stock betas decrease …

issue is particularly important for persistent time series, we focus on volatility modelling, specifically modelling of … realized volatility. We suggest a simple way of adjusting volatility models, which we illustrate on an AR(1) model and the HAR … more than 15 years, and we find that our extension improves the volatility models—both in sample and out of sample. For HAR …

strongest during bad economic times. In line with this evidence, we document that stock volatility predictability is also state …-series volatility models, in this paper we comprehensively examine how volatility forecastability varies across bull and bear states of … the stock market. We find that the volatility forecast horizon is substantially longer when the market is in a bear state …