1. Aaa is the highest possible bond rating from Moody's.
2. A bond with a rating of BBB is considered junk.
3. Bonds rated Ba or B are considered to have high risk.
4. A rating of CCC or lower from Standard & Poor's is considered investment grade.
5. Bonds rated D are in default.
6. Bonds rated Aaa have the highest risk.
7. The lowest investment-grade bond rating is Baa from Moody's and BBB from Standard & Poor's.
8. Bonds rated Caa by Moody's are classified as investment grade.
9. The highest bond rating from Standard & Poor's is AAA.
10. Bonds rated AA by Standard & Poor's are considered riskier than those rated A.