This excerpt taken from the NDAQ 10-Q filed May 9, 2008.
We are exposed to clearing risk.
We clear a range of equity-related and fixed-income-related derivative products. We assume the counterparty risk for all transactions that are cleared through our markets and guarantee that our cleared contracts will be honored. As protection against the risks that are associated with our derivatives clearing business, we enforce minimum financial and operational criteria for membership eligibility, require members and investors to provide collateral, and maintain established risk policies and procedures to ensure that the counterparty risks are properly monitored and pro-actively managed, but none of these measures provides absolute assurance against defaults by our counterparties on their obligations. Moreover, while collateralizing member and investor risk exposures is designed to ensure that sufficient collateral is maintained to compensate for the default risk incurred, no guarantee can be given that the collateral provided will at all times be sufficient. Although we maintain clearing capital resources to serve as an additional layer of protection to help ensure that we are able to meet our obligations, these resources may not be sufficient. In addition, our high leverage could limit our flexibility in the operation of our clearing business.