This guide outlines the evolving role of Chief Information Security Officers (CISOs) in the financial services sector, particularly in the context of increasing risks associated with artificial intelligence (AI) and regulatory compliance. It details findings from a survey of 650 CISOs, highlighting the complexities of their responsibilities, which now include managing AI governance and ensuring secure software development. The document emphasizes the collaboration between CISOs and other C-suite executives, noting that 66% of CISOs work closely with roles such as CFOs and legal officers to achieve organizational goals. Furthermore, the guide discusses the adoption of AI technologies within security functions, revealing that a significant majority of CISOs have integrated AI tools to enhance productivity and threat management. It also addresses the challenges faced by CISOs, including the need for better cybersecurity fluency among peers and the balancing act of leveraging AI while safeguarding sensitive data. The guide concludes with strategies for improving security outcomes and communicating the value of security initiatives to leadership.