Mortgage-Backed Security

S&P Slashes Ambac to Junk on Expected Losses 

Bond insurer Ambac Financial Group [stock ABK][/stock] this week estimated statutory impairment losses on credit derivatives for its Ambac Assurance segment rose by $1.6bn to a total $4.9bn in Q209. These losses, which the firm expects to report on August 5, are tied to collateralized debt obligations on asset-backed securities, the underlying collateral of which continues to decline in performance.