Book Description
Recent literature on stock return predictability suggests that it varies substantially across economic states being strongest during bad economic times. In line with this evidence, we document that stock volatility predictability is also state dependent. In particular, using a large data set of high-frequency data on individual stocks and a few popular time-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 than when it is in a bull state. In addition, the volatility forecast accuracy is higher and forecast bias is lower when the market is in a bear state. Our study concludes that the stock volatility predictability is strongest during bad economic times proxied by bear market states.
