This paper provides an evolutionary perspective on financial systems based on complex systems theory. This perspective is used to organize the discussion about the convergence and non-convergence of financial systems. Based on a notion of financial systems as configuration of complementary elements, it is suggested that the convergence of financial systems is best conceptualized as a path-dependent process of institutional change and innovation. The implication of the evolutionary perspective on the dynamics of financial systems is that neither convergence theories using a simple evolutionary argument of survival of the fittest nor divergence theories related to strong complementarities can provide much guidance for analyzing institutional transformations of financial systems.