What do S&P, Fitch and Moody's Ratings Mean?
Standard & Poor’s (S&P) Moody’s and Fitch are the three most significant rating agencies in the world. These agencies rate the creditworthiness of countries and private enterprises.
“AAA” or “Aaa” is the highest rating across all three rating agencies and indicates the highest level of creditworthiness. A “D” rating (“C” rating from Moody’s) indicates poor creditworthiness of a company or government. A difference is made between short-term and long-term ratings.
See creditworthiness ratings of Swiss banks