The risks subject in economic theory is disturbing and appealing in the same time and it has inspired one of the most precious pages of the modern economic thinking. Risk has fascinated, but also intimidated the economic operator who, motivated by the hope of profit, accepted to be terrorized by the deficit specter.  In this context the interest and actuality of the risks in economic relations subject appears clearly. The need to know and control it, in theory but also in practice, justifies by itself. This essay aims to clarify certain features of risk placed at the horizon of business.