This paper examines relationships between size and risk in financial markets. Based on the work of Makridakis / Taleb [2009] and Taleb / Tapiero [2009], presents the problems of excessive risk and imbalances caused by the size of firms. Markets mixed on firm growth traps externalities can influence risk, high-cost for the commons. A policy of regulation and control in markets, while necessary, are still insufficient in economies with little institutional support. Externalities of risk and firm size categories are fundamental to understanding the present financial crisis since the economies of scale.
