SUMMARY
The COVID-19 outbreak has become a global problem affecting human life entirely. This paper provides evidence of the market reaction to Jokowi’s announcement regarding the first patient of COVID-19 in Indonesia on March 2, 2020. This research is an event study that looks at whether or not there is a difference in average abnormal returns of 'go public' companies registered on The Jakarta Islamic Index (JII) 70 both before and after the announcement. The observations were made 9 days before the announcement and 9 days after the announcement. Based on descriptive data, the average stock returns of JII 70 fluctuated which increased on the first day after the announcement but decreased sharply after the fifth day of the announcement. The test showed that the average abnormal returns are negative both before and after the announcement. The paired sample t-test provided evidence that there is a difference in the average abnormal return during the testing period between before and after the announcement. The market reacted negatively to the announcement indicated by negative average abnormal return and support a semi-strong market hypothesis.========================================================================================================