This study investigates the impact of mega-sporting event announcements on the host country's stock market. The analysis includes 34 events between 2000 and 2024, including the Olympic Games (Summer and Winter), the FIFA World Cup, and the UEFA European Championship.

Employing a deductive approach grounded in existing theory and research, the study formulates hypotheses and utilizes an event study methodology to examine whether the announcements trigger abnormal returns in the host nation's stock market. T-tests are used to assess the statistical significance of the findings.

The results provide limited evidence of market reactions to the announcements, with any potential effects occurring primarily before the official announcement, suggesting the possibility of information leakage or insider trading. No significant effects were found on the announcement day itself or on subsequent days. Furthermore, no statistically significant differences were found based on the economic size of the host nation or the type of event. However, the study did observe that FIFA World Cup announcements tend to generate slightly more volatile market reactions compared to the other events.