Asymmetric and negative return-volatility relationship: the case of the VKOSPI

This study examines the short-term relationship between stock market returns and implied volatility using  high frequency data . This is the first study to analyze  high frequency data on the VKOPSIa newly introduced volatility index implied by the KOSPI200 options.  KOSPI 200 optioins  are the  most actively traded derivative contracts in the world and trading is dominate by  individuals. We find a strong asymmetric and negative return-volatility relationship both at the daily and intraday frequency, which cannot be explained by the standardhypotheses on the asymmetric volatility effect. Our results also show that the relationship is more pronounced in the presence of  extremely negative stock market returns.