The research “Countervailing market power analysis: assessing monopolisation tendencies in business environment of the modern financial service sector” provides a multi – perspective description of the nature, the occurrence sources and the specifics of monopolisation process development in the business environment of the modern financial service sector. The conducted research provides an example of quantitative analysis method application within a unified evaluation framework, while focusing on competitive environment evaluation in the relevant specific industry. The main scope of the aforementioned research is devoted to further developing the existing monopolistic tendency detecting techniques and quantitative analysis practices, while simultaneously considering the broader context of the market power phenomenon, its structure, influence and effects within the chosen specific industry.