We reconsider the role of financial intermediaries in monetary economics, and explore the hypothesis that the financial intermediary sector is the engine that drives the financial cycle through fluctuations in the price of risk. In this framework, balance sheet quantities emerge as a key indicator of risk appetite and, hence, for the risk-taking channel of monetary policy. We document evidence that balance sheets of financial intermediaries provide a window on the transmission of monetary policy through capital market conditions. Short-term interest rates are found to be important in influencing the size of financial intermediary balance sheets. Our findings suggest that the traditional focus on the money stock for the conduct of monetary policy may have more modern counterparts, and suggest the importance of tracking balance sheet quantities.