By one estimate, 90% of international transactions were accounted for by trade before 1970, and only 10% by capital flows. Today, despite a vast increase in global trade, that ratio has been reversed, with 90% of transactions accounted for by financial flows not directly related to trade in goods and services.
Chapter 8, Bubbles And Crashes In Emergent Markets, p. 304. - Why Stock Markets Crash - Critical Events in Complex Systems (2003)