By 2006 MBIA had plunged into the much riskier business of guaranteeing collateralized debt obligations, or C.D.O. 's.
到2006年，MBIA开始参与到风险更高的为担保债务凭证提供担保的业务中。
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Bond insurers such as MBIA and Assured Guaranty, which took hits on mortgage securities they had “wrapped” with credit enhancement, are becoming more active too.
The American International Group, Fannie Mae, Freddie Mac, General Electric and the municipal bond guarantors Ambac Financial and MBIA all had triple-A ratings.