Tick size change on the Stock Exchange of Thailand

Abstract

This paper explores the impact of an exogenous tick size reduction on bid-ask spreads, depths, and trading volume on the Stock Exchange of Thailand (SET). On November 5, 2001, the SET implemented a tick size reduction on stocks priced below THB 25. Even though trading on SET is largely dominated by retail investors, the tick reduction produces similar empirical results found in markets where institutional investors are more dominant. Tick reduction on the SET is associated with declines in spreads, and quoted and accumulated market depths. The study finds no significant change in trading volume due to the reduction.