This study investigates the impact of uncertainty on the mean-variance relationship. We find that the stock market’s expected excess return is positively related to the market’s conditional variances and implied variance during low uncertainty periods but unrelated or negatively related to...

The KOSPI (Korea Composite Stock Price Index) 200 options are one of the most actively traded derivatives in the world. This paper empirically examines (a) the statistical properties of the Korea's representative implied volatility index (VKOSPI) derived from the KOSPI 200 options and (b) the...

The authors re-examine the return-volatility relationship and its dynamics under a new vector autoregression (VAR) identification framework. By analyzing two model-free impliedvolatility indices – the well-established VIX (in the United States) and the recently published VKOSPI (in Korea) –...