An investigation of return-volatility relationship using high-frequency VKOSPI data

Most previous studies examine the relationship between stock market returns and volatility using low frequency data such as daily or weekly basis. In this study, using the high frequency intraday data, we expand the scope of prior studies to investigate the relationship of short-term changes of Korea's implied volatility index (VKOSPI; Volatility Index of KOSPI200) with short-term market return. We examine the short-term return-volatility relationship with regression analysis and vector autoregression (VAR) equations. The evidence predominantly points to a return-induced, asymmetric, return-volatility relationship. We also find that the asymmetric return is stronger for a high return (upper 10%) than for a low return (lowest 10%).