Market Concentration of ESG Debt Securities in Central and Eastern European (CEE) Countries

The article examines the level of concentration in the ESG bond market in Central and Eastern European (CEE) countries over the period 2020–2025. The aim of the study is to assess the structure of this market in terms of value, volume, product composition, and sectoral distribution. The analysis employs the Herfindahl–Hirschman Index (HHI), which enables the measurement of concentration levels across the respective dimensions. The data are sourced from the Environmental Finance Data database. The results indicate that the ESG bond market in the CEE region is characterized by a high degree of geographical concentration, with the dominance of a limited number of countries, namely Poland, the Czech Republic (Czechia), and Hungary. At the same time, a very strong product concentration persists. Green bonds play a predominant role, while other types of instruments remain of limited significance. A high level of concentration is also observed in the structure of issuers and economic sectors. Despite an increase in both the value and number of issuances, no clear diversification of the market has occurred. The findings suggest that the development of the ESG bond market in CEE countries is uneven and is concentrated around a limited number of participants and market segments.