The thesis of this paper is that the evolutionary and institutionalist frameworks can be usefully applied in order to observe the financial phenomenon from an unusual but fecund point of view. The shared financial mechanisms can be interpreted in terms of social rules, which are able to coordinate the financial behaviours belonging to different agents, which aim to different goals. From this standpoint, any financial mechanism is a socially shared rule and, as such, it is an institution. Because of the institutions can be very different even when they govern very similar facts, it can be useful to choose some variable, which is assumed to be crucial, in order to classify them. The paper proposes the adoption of the spontaneous/intentional evolutionary dichotomy, and argues that it roughly corresponds to the Keynesian distinction between “enterprise” and “speculation” in the financial activity. Although it is not possible identifying the exact demarcation which divides entrepreneurial from speculative financial institutions, the paper suggests to take into consideration the prevailing purpose of their use in order to ensure a rudimentary differentiation. The point is that the speculative institution can not exist in the absence of an underlying entrepreneurial institution, whereas the existence of the latter does not depend on the existence of the former. It happens because the finance is a “spontaneous” extension of the entrepreneurial dynamic. The volitional element, which intervenes later in order to extract some speculative advantage from that activity, has to take that entrepreneurial institution as a basis. So, the entrepreneurial institutions show the usual characteristics belonging to the spontaneous institutions, whereas the speculative institutions are characterized by a strong presence of the volitional element. The more the distance of the financial institution from its evolutionary configuration (and from the underlying entrepreneurial institution), the more its affinity to the rule of an unnecessary gambling game.