This note examines the implications of digital innovation for market structure and attendant policies, including financial and competition regulation. There have been several surveys of regulatory responses. This note takes a step back, to look at what the economic theory of banking and financial intermediation can tell us about how technology may drive industrial organization in the sector, and how that might inform further policy responses. The paper roots the impact of the digital transformation of finance in innovations that have enabled providers to address long-standing challenges of financial intermediation, including asymmetric information, uncertainty, incomplete markets, and fixed and variable costs of production. The paper describes how digital innovation affects these key economic frictions in finance and alters the financial services value chain and industrial organization. The forces driving these changes, and potential outcomes in terms of industry structure, lead to insights for policy makers on how to harness the benefits of fintech, while mitigating some of the risks, particularly around competition and market structure. The focus is on economic and technological forces that apply broadly across financial services. It recognizes that the sector encompasses a wide range of different products and services and is composed of numerous sub-markets that might use different technologies or have different economic structures. These may thus diverge in market structure and competition outcomes.