Given banks’ role in global financial markets, there is growing concern about cyber incidents' impact on broader financial stability. Recent research has focused predominantly on the banking industry as a whole and investigated the aggregate impact of cyber incidents on deposit balances, capital ratios, and operational losses. Little is understood about how risk managers in banks assess the financial impact of a potential cyber incident. Even in banks that feature a high degree of cybersecurity process maturity, there is a continued perception that the impact of a cyber incident remains financially unquantifiable. This study explores how executives in banks currently manage their cyber risk exposure and how a financial quantification model can be designed to capture the impact of a cyber incident. An Australian bank formed the setting for our exploratory case study. Interviews revealed that bank managers consider maintaining customer trust and reputation a key priority following a cyber incident. We developed, tested and validated a conceptual model aimed to guide cybersecurity experts and risk managers in the financial quantification of the impact of a cyber incident in banks.