US Residential Mortgage Market

The area of UBS most severely affected by the progressive market dislocation during 2007 is the fixed income, currencies and commodities (FICC) business, which has positions in securities related to the US residential mortgage market in a number of portfolios. The deterioration of this sector was more sudden and severe than any such event in recent market history. As a result, the securitized credit markets became illiquid and UBS's positions, including securities with high credit ratings, lost substantial value. These difficulties persisted throughout third quarter 2007, with further deterioration in fourth quarter 2007 as increasing homeowner delinquencies fuelled market expectations of future writedowns. During fourth quarter, monoline insurers were adversely affected by their exposure to US residential mortgage-linked products.