In the financial world, it has long been relevant and interesting to examine how various events and news from around the world affect stock market movements. The significant commercial development of sports in the past decade, particularly the intense economic growth of football, has given the sport a greater impact on the broader economy. The results of football matches can be seen as both events and news contributing to new information and may therefore, in accordance with theories such as the efficient market hypothesis (EMH), affect the financial market. The purpose of this study is to investigate whether the match results (win or loss) of the three largest men's football teams in Stockholm (AIK, DIF, HIF) have an impact on 13 selected companies on the Stockholm Stock Exchange over a 9-year period. The study adopts a quantitative approach and is an event study. The empirical data for the study are obtained from the Nasdaq database. The event window will occur when all Stockholm teams win or when two out of three lose (since there were hardly any instances where all lost simultaneously), followed by the calculation of the potential abnormal returns that may arise as a result of the match outcome. The calculation will take place on the next trading day afterthe match ends. Since the study spans from 2015 to 2024, and wins/losses occur multiple times per year, multiple event windows and estimation windows will be used each year. Estimation windows always span 120 days before the event days. Through the theories of EMH and behavioral finance, the selected Stockholm companies are studied in accordance with the study's method. The results show, among other things, a positive CAAR in most winning occasions, while the instances of loss are distinctly predominantly negative. However, the hypothesis testing of the study suggests that there is a high risk that factors beyond match results have influenced the results.Previous research on the subject is relatively divided on the question of the impact of sports results on stock markets. A study by Gerlach (2011) indicates that there is no direct correlation or impact. And Ashton, Gerrard, and Hudson's (2003) results suggest that the results of more significant matches may affect the so-called "next day return" on a stock market.Keywords: Event study, football matches, sports results, sports performances, stock mar