Insurance companies manage riskโ€”their own risk. When it comes to insuring new-issue muni bonds, the only game in town is Assured Guaranty Ltd. Theyโ€™re staring down the barrel of a ratings downgrade by Moodyโ€™s Investors Service. Risky muni-bond investing is about to get riskier.

Check out The Wall Street Journalโ€™s For Muni Bonds, Less Assurance:

The last remaining insurer of new municipal-bond issues is bracing for a fall that could bring its industry to a new lowโ€”and possibly increase borrowing costs for some small local governments.

Moodyโ€™s Investors Service warned in late March that it might cut bond-insurer Assured Guaranty Ltd.โ€™s AGO +0.08% credit rating to the single-A range from the current Aa3, which is three notches below the highest rating of triple-A.