The fact that a third contribution in this book series now focuses on the political-economic categories of share capital and the joint-stock company (Dellheim 2018, pp. 265–298; Dellheim 2023, pp. 329–366) again is justified by their relevance for the genesis and development of the capitalist mode of production. Varga wanted to understand why the distinct economic, economic-political, political and military actors act as they do and what this means, in turn, for the political conditions of action of socialist actors. In this book chapter, we are first interested in the extent to which Eugen Varga enriched our knowledge of share capital, respectively joint-stock companies, and the corresponding development of capital relations in his examination of this complicated problem. Second, we are interested in what those who work to continue Marx’s critique of political economy today can learn from Eugen Varga’s contributions to the political, ideological and scientific debate.