11  Some industry sources suggest that the mortgage market is getting more concentrated at the top. The share of mortgage-related activity of large banks is greater if market share estimates are based on both the number of loan originations and loan purchases.
The complexity of CDOs is one example of a widespread increase in the complexity of the capital market activities in which the largest banks now engage. Some banks' failure to adequately manage this complexity has weakened financial stability in the current market turmoil. CDOs and other structured credit products can be very complicated.