This has prompted calls for heightened surveillance, including a wider role for the Bank for International Settlements (BIS), the Swiss-based central banks' central bank.

CNN: In Search of a Tougher Cop

The Bank for International Settlements (BIS) argued in its recent annual report that huge growth in bank reserves was driving overnight-lending rates to zero, causing the market for unsecured overnight lending to atrophy.

ECONOMIST: Quantitative easing: QE, or not QE? | The