 It is estimated that almost half of all outstanding interest rate swap transactions are centrally cleared.The systemic importance of CCPs is expected to increase further as the central clearing of standardized over-the-counter (OTC) derivatives becomes mandatory in line with commitments made by G20 leaders following the crisis.The Financial Stability Board reported in April 2013 that, as at the end of February 2013, around US$158 trillion of interest rate swaps and over US$2.6 trillion of OTC credit derivatives were centrally cleared, representing 41% and 12% respectively of total outstanding notional amounts.