In 2012, American “prime” money-market funds, which buy bank and corporate debt, were worth nearly $1.5 trillion. The money flowing through these funds went to many of the world’s largest banks, including not just the obvious US suspects (JP Morgan Chase, Bank of America, and Citi), but also major European and Japanese banks such as Barclays, Deutsche Bank, Bank of Tokyo, Sumitomo, Credit Suisse, and ING.