Structured Products Markets and Implied Volatility Distortion

Abstract

This study verifies the existence of implied volatility distortion by the rapid growth of structured products such as Equity Linked Securities (ELS) in Korean financial markets and provides the policy implications to overcome such a distortion. The most ELS products issued in Korea have a step-down auto-callable payoff structure consisting of short position in down-and-in barrier put options and long position in digital call options. Financial companies which have issued ELS are exposed to the volatility risk, i.e. long vega position, and tend to execute the volatility transactions of short vega. For instance, the financial companies issue Equity-Linked Warrants or sell listed/over-the-counter vanilla options, both of which have short position in volatility risk. Accordingly, the demand for selling volatility is stronger than for buying volatility in the Korean financial markets. According to the empirical results, we conform that the rapid growth of the ELS products induces the pressure for lowering volatility and furthermore, the volatility spreads, defined as the difference between implied volatility and realized volatility, also decrease with respect the amount of the newly issued ELS. Lastly, to mitigate the volatility distortion effect, we suggest to list VKOSPI-related derivatives securities such as VKOSPI futures and options, which in turn balance the trading demands for selling and buying volatilities.

Citation

Yoon, S.-J. (2014), "Structured Products Markets and Implied Volatility Distortion", Journal of Derivatives and Quantitative Studies: 선물연구, Vol. 22 No. 3, pp. 433-464. https://doi.org/10.1108/JDQS-03-2014-B0003