The practice and theory of risk management for financial institutions has changed dramatically over the last twenty years. A plethora of new financial instruments has become available for trading and hedging purposes. Financial institutions have also become much more resourceful in taking advantage of differences in regulatory requirements across countries and across types of institutions. With all these changes, financial institutions that face financial difficulties often do so in ways that are hard to understand in light of traditional models of bank runs. Further, new types of financial institutions, such as hedge funds, have become markedly more important. Regulators have attempted to respond to financial innovation with more flexible capital requirements that make greater use of the risk management models of financial institutions and with more risk-focused supervision. These changes in financial institutions and the financial system mean that many theories of financial institutions have become materially incomplete and that our current understanding is deficient. The goal of the NBER Working Group on the Risks of Financial Institutions is to improve our understanding of the risks of financial institutions, of how these risks can be measured and managed with new techniques and new financial instruments, of how these risks are affected by new risk management technologies and new financial instruments, of how regulations and capital requirements impact these risks, of how the risks differ across types of institutions, and of whether the risks pose threats to the financial system. The Group will meet several times a year to discuss new research of interest and to receive input from industry participants and regulators.