A junk bond rating assigned to fairly speculative debt instruments. A CC rating indicates the issuer is at greater risk of default than a CCC-rated issue and less than a C-rated issue if business, financia, or economic conditions change measurably. Bond investors rely on bond ratings from organizations like Standard & Poor's, Moody's Investors Service, and Fitch Ratings to evaluate the default risk associated with both corporate bonds and municipal bonds. Compare to Investment Grade.