This research paper analyses the impact of COVID-19 on the ASEAN countries such as Japan, China, Indonesia, India, Malaysia, Vietnam, Thailand, Russia, Singapore, and South Korea, which are developing financial markets. It could be identified from the analysis that each index fell when it occurred, and what is the overall performance of the index throughout the year by implying the change in percentage of the index value. In this, the study concluded that the outbreak of COVID-19 is the major cause of such a crash, where people have no idea of what is going to happen, and that created a huge fear and triggered an uncontrollable selloff. And now, after the corrective measures from the government, the markets around the globe have the clarity to handle such crises and adapt to such situations.