Birla reveals how the categories of public and private infiltrated colonial commercial law, establishing distinct worlds for economic and cultural practice. This bifurcation was especially apparent in legal dilemmas concerning indigenous or “vernacular” capitalists, crucial engines of credit and production that operated through networks of extended kinship. Focusing on the story of the Marwaris, a powerful business group renowned as a key sector of India’s capitalist class, Birla demonstrates how colonial law governed vernacular capitalists as rarefied cultural actors, so rendering them illegitimate as economic agents. Birla’s innovative attention to the negotiations between vernacular and colonial systems of valuation illustrates how kinship-based commercial groups asserted their legitimacy by challenging and inhabiting the public/private mapping. Highlighting the cultural politics of market governance, Stages of Capital is an unprecedented history of colonial commercial law, its legal fictions, and the formation of the modern economic subject in India.