Ambac ... became the first bond insurer to lose its AAA rating after Fitch Ratings downgraded the company.Moody's and S&P are also reviewing the bond insurers, see:
Ambac Assurance Corp. was lowered two levels to AA and may be reduced further ... Fitch said today in a statement. ... The downgrade throws doubt on the ratings of $556 billion in municipal and structured finance debt guaranteed by Ambac.
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The seven AAA rated bond insurers place their stamp on $2.4 trillion of debt. Losing those rankings may cost borrowers and investors as much as $200 billion, according to data compiled by Bloomberg.
S&P: Bond Insurer Review to be Completed Next Week
Moody's: Ambac Under Review for Possible Downgrade