Credit rating indicating a relatively low level of default risk that is awarded by Moody’s Investors Services; other companies provide ratings expressed in slightly different terms. The highest rating conferred by Moody’s is AAA, given to a security with the greatest margin of investor safety against credit loss, even under severe economic conditions. The lowest rating, C, is assigned to a bond with a high probability of defaulting. Bonds rated from BAA to just short of Aaa are considered "investment grade." Those rated BA and below are "speculative grade." Moody’s provides a finer gradation of credit risk with numerical modifiers, such as A3 and BAA1.