The problem of theory and methodology of financial services market research was and remains quite relevant. The scientists of the world have not finally decided on which scientific theory (theories) to base research on the development of the modern market. Therefore, the question remains open, which concept and methodology should be used for the analysis and forecast of its situation in order to obtain results that would most accurately reflect and explain the current situation and would provide a forecast of the development of this market for different perspectives, would provide tools for management business in the conditions of the conjuncture, which is expected. This article analyzes various economic theories and concepts that were dominant in the study of the problems of the development of the financial services market during the last centuries. As a conclusion, a mix of neoclassical, neo-Keynesian, new institutional theory and the theory of asymmetric information turned out to be the most appropriate for modern research. Such a comprehensive approach allows you to consider the market of financial services as a multifaceted and diverse phenomenon and to use a wide range of approaches, methods, tools, combining them within the limits of modern methodology. The main approaches used in the study were complex and systematic, which allow, after calculating the capacity of individual market segments, to arrive at indicators of the total capacity of the financial services market. In the process of research, the essence of the financial services market was determined, it was segmented according to various characteristics for deeper research, the place of each segment in the financial market system was invented, appropriate methods of analysis and forecasting of the development of segments of this market were outlined, approaches and methods of regulating market processes on them were determined. In the conditions of a full-scale war in Ukraine, it is extremely important to correctly determine the capacity of the financial services market in all its segments, to understand how important this source can be for the recovery and development of the national economy, to competently develop and regulate this market.