Credit rating agencies assign credit ratings to issuers of debt to indicate their level of risk. The three largest agencies are Standard & Poor's, Moody's, and Fitch, which together control around 95% of the market. The rating process involves analysts collecting financial information from issuers and assessing risks like an issuer's business profile, cash flow adequacy, and likelihood of default. Credit ratings impact issuers' borrowing costs and their ability to access financial markets. While ratings provide useful information to investors, credit rating agencies have also received criticism around potential conflicts of interest.