This study is conducted to scrutinize political event effect towards the stock liquidity and market reaction in Indonesia. 2019 Presidential Election is being the focus of the study and using both abnormal return and bid-ask spread as the parameter of the study. The samples of this study are listed stocks from both LQ45 and PEFINDO25 Index that are actively traded on April 3, 2019 to May 1, 2019. Parametric t-test and paired sample t-test are being utilized to measure the hypotheses. Overall, the results of the study explain that the market is not significantly react to the presidential election and this can be understood because market has already hypothetically known the winner of the election previous of the announcement in media. This study also strengthens the major studies that Indonesia Stock Market is not an efficient market

Keywords : component; Abnormal return; bid-ask spread; paired sample t-test; Indonesian president and vicepresident election.