Den kortsiktiga marknadsreaktionen vid M&A : En eventstudie om hur aktievärdet påverkas vid förvärv av börsnoterade bolag inom Norden mellan 2013 och 2025

Sammanfattning

This study examines the short-term stock market reaction to announcements of horizontal acquisitions carried out by publicly listed companies in the Nordic region during the period 2013–2025. The purpose is to analyze whether acquisition announcements give rise to abnormal returns (AR) and cumulative abnormal returns (CAR) for the acquiring firm within an event window of −5 to +5 days around the announcement date. The study applies a quantitative event study methodology, where normal returns are estimated using OLS-regression against the VINX Benchmark Index (SEK). The sample consists of 64 horizontal acquisitions, and statistical significance is tested using a t-test at the 5% significance level. The results show that acquiring firms, on average, exhibit a positive abnormal return on the announcement day, with an AAR of 1.58%, which is the highest value within the event window. However, since the result is not statistically significant, this should be interpreted as a positive tendency in the sample rather than as a statistically confirmed market reaction. Therefore, the findings suggest that the market may react positively to acquisition announcements, but the evidence is not strong enough to reject the null hypotheses. The result is analyzed based on the efficient market hypothesis and behavioral finance.