Using evolutionary game theory, this work aims to analyse the interactions between debt issuers and credit rating agencies in an asymmetric information environment. While the ratings grades are required by issuers to access funding sources for their investment projects, the agency s revenue is provided by this service. The results show that when the number of investment grade issuers is small, non-transparency strategy and basic methodology of analysis dominate, worsening the information asymmetry problem. The increase in the number of investment grade issuers encourages transparency policies while the agencies adopt a sophisticated analysis, avoiding the reputation costs associated with errors. Empirically, the results are consistent with the evolution of the Colombian economy in recent decades. The country s improvement in the macroeconomic environment attracted investment grade issuers encouraging the proliferation of sophisticated rating agencies and transparent issuers.