New regulation in the tick price and lot size was implemented in Indonesia Stock Exchange on 6 January 2014. This research aims to examine the effects of the changes toward stock liquidity. Comparison of stock liquidity measurement variables before and after the event is conducted with 15 days window period. 370 stocks fulfilled the criterion and used as sample in this paper. This study employs paired sample t-test for normally distributed data and Wilcoxon test for not normally distributed data to assess mean significant differences before and after the event. Result shows that to some extent, the event enhanced stock liquidity
