A central aspect of historical research is to provide explanations for the causes and effects of events that occurred in the past, in particular the Second World War. History can be analyzed and explained from different perspectives. Two such perspectives are considered, the first being the traditional historiographic approach, in which the main emphasis is on the qualitative analysis of various kinds of historical sources and documents, and the second being what we call the financial market approach, a recent methodology for linking significant changes in historical market prices to simultaneously occurring geopolitical events. The fundamental characteristics of the two approaches are identified and compared in answering some important historical questions concerning the Second World War. The financial market approach, as reflected in the secondary market for government bonds, is studied for various countries. Both approaches rely heavily on interpretation – but in different ways. They complement each other in a useful way.