In the past two decades, the financial system of most transition countries has developed significantly better than the economies themselves. A new regulatory framework has been introduced and new financial institutions have been founded that will contribute to better financial development and macroeconomic stability. In addition, deregulation of the system and strong effects of privatization culminated in the influx of new (foreign) market players and created increasing pressure on the competitiveness of the overall market. In general, banks today enter the unexplored - non-banking markets, financial institutions into liberalized banking markets, which ultimately serve it. Such long-lasting effects have resulted in a reduction of the market and market structure, which has been reflected in the behavior of market players whose foundations are based on neoclassical economic theory. Market concentration is the basic measure of market power and therefore plays a key role in the theory of imperfect competition. Whereas the Croatian market today is increasingly characterized by the supremacy of large market players, the measurement and analysis of concentration; especially the financial markets is crucial for the effective functioning and economic progress of the entire system. The focus of this study is all the present integrations (horizontals) that cause a permanent change of the industrial structure, analyzing the concentration of the copper and insurance markets in the Republic of Croatia over a ten years period from 2009 to 2018. The last two-year period for which the analysis was conducted has been followed by expansion of economic activity and further consolidation of the sector, and their effects will be shown within this study. In addition, the concentration on the banking market will be compared with the concentration of the insurance market, and its importance will be identified for the efficiency of the entire sector