Information Contents of Order Flow Toxicity in the Options Market : The Case of KOSPI200 Index Options

Abstract

This study estimates the VPIN (volume-synchronized probability of informed trading) of the KOSPI200 index options, the measure of order flow toxicity suggested by Easley et al. (2012), for the first time. To apply the VPIN approach, options are categorized by their real-time moneyness. I examine the predictive power of VPIN for the future stock market volatility using time-series regression analysis. The empirical result shows that the toxic order flow measure estimated by price changes has more information than that estimated by the actual order imbalance. In general, put options contain more information than call options, and the toxic order flow measure of OTM (out-of-the-money) put options contains the most significant information about the future stock market volatility. In addition, the predictive power of toxic order flow measure is much significant in the highly volatile than in the stable market. The volatility predictability of toxic order flow measure declined significantly after the option multiplier increase, whereas it has gradually recovered over time.