Rama Cont Imperial College Understanding the mechanisms underlying systemic risk requires to change the traditional focus of risk modeling and examine the link between the structure of the financial system and its stability, with a focus on contagion mechanisms which may lead to large scale instabilities in the financial system. Some channels of contagion which have played an important role in past crises are: insolvency contagion through counterparty exposures [1,2,3], withdrawal of liquidity in funding channels and price-mediated contagion [4,5] through fire sales of assets. We review some recent work on the mechanisms underlying these channels of contagion, with a focus on the nature of the ‘network’ underlying each contagion mechanism and the implications of these results for the monitoring and regulation of systemic risk. In particular, we will attempt to illustrate the importance of the interaction between these various channels and how this interaction may undermine regulatory efforts focused only on a single mechanism.