The banking and financial services sector is undergoing profound transformation driven by digital innovation, new market entrants, and a fragmented and asymmetric regulatory environment. This dissertation examines how firms in the evolving banking ecosystem create and capture business value amid competitive dynamics shaped by both competition and cooperation. The research question guiding this study is: How will firms in the evolving banking ecosystem create and capture business value given the asymmetric and fragmented regulatory environment and changing competitive landscape? This study conceptualizes these dynamics as coopetition, where traditional banks, fintech firms, and Big Tech companies collaborate while simultaneously competing. To address this question, the dissertation uses an exploratory qualitative design. Drawing on the Technology–Organization–Environment (TOE) framework, the International Risk Governance Council (IRGC) risk framework, and platform theory, the study explains how value creation and capture, risk governance, and platform ecosystem positioning interact in a digitally transforming financial system. The findings show that small banks, fintech firms, and Big Tech companies adopt distinct yet interconnected strategies to compete and collaborate within the financial services ecosystem. Small banks, often constrained by limited internal resources, create and capture value through collaborations that either enhance customer-facing digital capabilities or provide white-labeled banking infrastructure that enables fintech firms to deliver financial services under their own brands. The dissertation identifies key regulatory risk exposures in these partnerships and outlines governance guidelines to help institutions manage risk while sustaining strategic growth. At the ecosystem level, the growing involvement of Big Tech firms is likely to reshape the banking sector. Through scenario analysis grounded in platform theory, the study shows how different cooperative and competitive models between banks and Big Tech firms can redefine market boundaries and redistribute competitive power. This dissertation contributes to scholarly research and practice by explaining how ecosystem components interact to shape product development and competitive dynamics, how different collaborations introduce regulatory risks, and how technological infrastructures, organizational strategies, and regulatory environments jointly determine which products are developed and how they scale. It also offers future scenarios to help decision makers rethink assumptions and navigate the rapidly changing banking landscape.