Barunik, Jozef; Barunikova, Michaela - 2015
This paper revisits the fractional co-integrating relationship between ex-ante implied volatility and ex-post realized … volatility. Previous studies on stock index options have found biases and inefficiencies in implied volatility as a forecast of … future volatility. It is argued that the concept of corridor implied volatility (CIV) should be used instead of the popular …