The article studies the historical and logical relationship of the transformational and transactional functions of economic activity: it determines the belonging of the abovementioned concepts to the categorical core of economic science; it specifies their characteristics and volume; examines the features of realization of the studied functions in various historical conditions. As the primary method, we used the structural-logical analysis of empirical and theoretical research results on the topics covered. Transformational activity, according to the author, expresses the dialectical unity of production and consumption. The transaction is analyzed as a technological (O. Williamson) and/or legal (J. Commons) link between these processes. The origin of transactions is associated with the emergence of a transformational surplus designed to meet rising needs. The available historical and ethnographic data allows us to trace this phenomenon retrospectively to the moment of the formation of social production. The economic content of transactions is derived from the dual nature of transformational activities aimed at (1) the creation of material products and (2) the objectification of technological information that determines distribution (transport, trade, housing and communal services, etc.). Their implementation is provided by administrative and legal services expressing ownership of the exchanged goods. It increased the efficiency of transactional support of human life with the use of money as a virtual bearer of economic information and a universal measure of the value of a commodity. In conclusion, the author raises a question about the nature of technological and economic shifts in the modern market economy, coinciding with the outstripping growth of transaction costs. Using the world-system approach of F. Braudel makes it possible to put forward a hypothesis about the transactional revolution that preceded the industrial revolution and is manifested in the rapid increase in financial assets.