Financial technology (FinTech) encompasses a new wave of companies developing new products and platforms to change the way businesses and consumers make payments, lend, borrow, and invest. This chapter examines the ways in which FinTech products and services are reshaping the intermediation function of banks, and how financial institutions have engaged with FinTech firms in different ways, resulting in variegated forms of organizational change, inter-firm relationships, and changing production and financial networks. Setting up banks and technology firms as direct competitors in the FinTech ecosystem, as ‘incumbents’ versus ‘disruptors’, overly simplifies their position and power in different product segments, geographical markets, and industry networks. Instead, a financial ecologies approach offers greater flexibility for studying shifting configurations of economic actors across banking and FinTech sectors, with important implications for how we understand the nature of financial/non-financial firms, the changing roles of international financial centers, and the nature of inter-firm and inter-industry networks in global finance.