Cyberattacks and business performance: Sectoral evidence from stock market reactions

The article examines the impact of cyberattacks on the market capitalization and short-term returns of leading companies in the finance, telecommunications, and information technology (IT) sectors. Using event analysis, abnormal return (AR), and cumulative abnormal return (CAR) estimation, the market sensitivity to cybersecurity incidents is determined for over 30 events over the period 2018–2024. The results indicate a short-term negative effect of cyberattacks, especially in the financial sector, while technology companies demonstrate a faster recovery of market positions. Differences in investor risk perception are identified depending on the industry, the duration of the attack, the history of previous incidents, and the reputational stability of the company. Cases of repeated attacks on one company are analyzed separately, indicating a change in the intensity of the market reaction over time. The findings complement existing empirical evidence on stock market sensitivity to cybersecurity incident disclosures documented in prior event-based studies (Cavusoglu et al., 2004; Romanosky, 2016) and provide insights for improving cyber risk management strategies, particularly with respect to disclosure practices and reputational shock monitoring systems.