How did bankers make their investment decisions, for example to issue a state loan for a peripheral country? This in-depth case study investigates the question of the Greek loan of 1833, issued by Rothschilds. The main interest is to reconstruct James de Rothschild’s risk perception and decision making process, expressed in the argumentation vis-à-vis his family. The significance of the guarantee of the protecting powers, which was without precedent, is considered by James as well as the competitive situation on the bond market, the relationship of the Rothschilds with leading politicians of the time, and the special significance of Greece in the period of intensive European philhellenism. The paper argues that in-depth studies of bankers’ risk perception are necessary to illuminate the complexity of their decision-making.