In the discussion on the causes of the financial crisis three main lines of argument can be distinguished: The „regulatory failure“ argument, the theory of the cyclical instability of financial markets, and analyses of „financialization“. From a sociological point of view, the latter analyses deserve particular interest, as they consider the crisis in the context of the larger structural changes of mature capitalist societies that have developed since the last decades of the 20th century. The paper first provides an overview of the financialization literature, focussing of the interplay between the changes on the macro-, meso- and micro levels of society that led to the present dominance of the financial services sector over the economy. Moreover, the historical analyses of Arrighi and Silver are considered. The second part of the paper offers a theoretical reconceptualization of the empirical findings in the framework of a multilevel model of capitalist dynamics. The model shows how a prosperous capitalist economy like the Western one in the second half of the 20th century can be transformed into a financialized economy due to its own internal dynamics. From a sociological perspective, financialization can thus be understood as a hegemonial regime of financial investors over entrepreneurs.