The market for foreign currency is the largest in the world. A 1989 Bank for International Settlements (BIS) survey concluded that the average daily value of foreign currency transactions (based on April of that year and net of double counting) was around $640 billion (BIS 1990: 208-11). Assuming 250 working days in a year, that translates to $160 trillion annually – enough to finance world trade over 35 times. US GDP that same year was $5,244 billion, or one-thirtieth of the value of currency transactions.