Derivatives markets : from bank risk management to financial stability.

Summary In its first part, this thesis studies the optimal use of derivatives by financial intermediaries in their risk management, with specific attention to the interest rate derivatives market. By modeling the optimal capital structure of a bank, the first chapter shows how the optimal use of derivatives affects some decisions often studied in corporate finance: credit supply, maturity transformation, dividend policy or default probabilities. The second part of the thesis studies the derivatives market as a system in its own right. The second chapter uses a new and unique database of bilateral exposures on CDS contracts to provide a detailed description of the structure of the exposure network. The third chapter focuses on the regulation of derivatives markets. It studies the central clearing of standardized derivatives, and the demand for collateral induced by this reform on a global scale, under a variety of assumptions about market microstructure.