In order to perform their multiple tasks, CCPs should do the following: a) regard themselves and act as system risk managers; b) avoid heavily procyclical margining policies; c) monitor the soundness of their clearing members and the risks they bring to the CCP. He calls for debates on whether clearing houses should set margin requirements on a gross basis rather than net; whether macro-prudential authorities should vary minimum margin requirements over the cycle; and on the development of an ex ante resolution framework for limiting disorder if a CCP were ever to fail.