The semiotics of economic transaction is here presented as a new approach to the mechanisms of the transaction of economic value. After analyzing the nature of the main semiotic device for value transactions - the money sign - we identify, at its core, the trust in the future of the economic system of exchange and the scarcity of its availability as a condition for its value and meaning. Such characteristics lead us to search for theoretical support in the existential analytics of temporality devised by Heidegger, where we find a homology between economic scarcity and the thesis of the primordial finitude of temporality, which is a scarcity of time. Thus, we distinguish between two levels of semiotic analysis of transactions: a deep/authentic level of the primordial formation of value and a superficial level of commercial practices of market exchange. From this point of view, the new digital economy seems to bring closer the two levels, transforming the availability of time for each person into the major economical resource. The study ends with some critical remarks from a semiotic perspective on neoliberal financial excesses.