IMPACT OF DERIVATIVE WARRANTS INTRODUCTION ON THAILAND STOCK MARKET VOLATILITY

Abstract

The Stock Exchange of Thailand (SET) first launched derivative warrants on SET50 index (SET50 DWs) on April 17, 2014. They are currently the most active DWs on the SET. This research uses the GARCH family models augmented with dummy variable to analyze the effect of SET50 DWs on stock market volatility. The sample data consist of daily returns of SET50 index from the period October 30, 2012 to December 30, 2019. The empirical results indicate that the coming into market of SET50 DWs reduces stock market volatility. The GARCH (1,1) TARCH (1,1), and EGARCH (1,1) models are not radically different from each other in their output. However, the asymmetric TARCH (1,1) model is found to provide the best fit in modelling volatility. The SET50 index shows the existence of leverage effect, where negative shocks have a greater impact on the volatility than positive shocks. Introducing SET50 DWs lowers the price volatility of SET50 index so investor having a portfolio investment with a correlation to the performance of SET50 index should adjust hedge ratio appropriately to manage investment risk. There is also a suggestion for policy makers to support the launch of DWs to lower the volatility in underlying spot market resulting in improved efficiency.