This study assesses the financial impact of cyberattacks on financial institutions by applying Monte Carlo simulations, ARIMA-based forecasting, and Value at Risk (VaR) and Conditional VaR (CVaR) models to quantify direct and indirect losses, including regulatory fines, operational disruptions, and reputational damage. A cost-benefit analysis determines the optimal level of cybersecurity investment, and correlation analysis evaluates the systemic risks posed by cyberattacks across the financial ecosystem. The research finds that institutions face an average loss of $427.28 million over 10 years, with potential losses rising to $705.01 million in worst-case scenarios. VaR suggests a maximum expected loss of $268.23 million, while CVaR points to potential extreme losses of $437.36 million. Time-series forecasting projects continued growth in cyber losses, reaching $114.68 million annually by 2028. The study also reveals diminishing returns on cybersecurity investments beyond $1 billion, though positive ROI persists. Predictive models for cyber insurance estimate premiums ranging from $10.60 million to $176.52 million, helping institutions optimize risk mitigation strategies. These findings underscore the critical need for financial institutions to integrate cybersecurity into broader risk management frameworks, balancing investment with financial returns to enhance resilience against evolving threats.