This article argues that the study of international political economy (IPE) in general, and the analysis of modern finance in particular, have much to gain from the insights articulated in poststructuralist international relations. In contrast to recent critiques of poststructuralism, this article argues that the study of international finance necessitates a consideration of the discursive practices which bring capitalist concepts such as money, profit and capital into being. Financial practices do not exist prior to, or independently from, ideas and beliefs about them. Thus, IPE should recognise the production of economic and financial knowledge as an important site where power is exercised.