This study is a study to empirically confirm the insolvency risk caused by the induction of large-sized securities companies after the introduction of the comprehensive financial investment business (extra-large securities companies) policy in the Korean capital market. Since the introduction of the polcy, there have been concerns that the expansion of the business scope of securities firms may expose them to various risks, such as high-risk investments due to leverage expansion, concentration of real estate PF assets deepening, and credit risk and interest rate risk due to trading of derivatives-linked securities. In this study, the impact of equity capital on insolvency risk was analyzed using a panel regression model for 39 domestic securities firms from the first quarter of 2009 to the fourth quarter of 2016, before and after the introduction of the policy in October 2013. Among previous studies, studies that presented positive results regarding the enlargement of financial companies focused on individual financial companies, while studies that presented negative results focused on the perspective of the financial system as a whole. The introduction of comprehensive financial investment businesses, which was the focus of this study, is a topic from the financial system perspective, so it is appropriate to conservatively examine the impact of policy introduction. Therefore, this study established the hypothesis that “the enlargement of securities companies following the introduction of the comprehensive financial investment business policy increases their insolvency risk.” The dependent variable of the analysis model is the natural logarithm of the default risk variables (EDF and Z-Score), and the independent variable is the amount of equity capital (natural logarithm) of individual securities companies. Other control variables include asset size (total assets (natural logarithm)), capital adequacy (NCR), profitability (ROE), asset soundness (NPL), and macroeconomic variables (GDP growth rate, housing price fluctuation rate, KOSPI growth rate). As a result, first, although securities companies are becoming larger in line with the purpose of introducing the comprehensive financial investment business policy, it was confirmed that their insolvency risk increased after the introduction of the policy. In other words, in the case of large securities companies, EDF increased and Z-Score decreased. Second, especially for super-large securities companies with equity capital of KRW 3 trillion or more, their insolvency risk increased significantly in proportion to the size of equity capital after the introduction of the policy, which can be attributed to the risk exposure due to the expansion of the scope of business. These results suggests the following: First, it needs to be intended to promote stability in the capital market by actively supervising the risk-seeking business of large securities companies following deregulation, and establishing risk-monitoring system in terms of macroprudentiality that can immediately intervene in their insolvency. Second, It can urge the awakening of all securities industry. In particular, in the process of reorganizing the sales and profit structures of securities industry due to the policy, it can be suggested that policies such as specialization strategies for small and medium-sized securities companies in order to minimize the negative impact of the relative weakening of their competitiveness. Finally, companies seeking to access the capital market can be expected to actively monitor the securities firms they deal with. This perspective is especially useful for small and medium-sized businesses. The insolvency risk of financial companies is inversely proportional to the financial inclusion of small and medium-sized businesses. Above all, without undermining financial stability, coordination and cooperation of market participants such as companies, investors, intermediaries, and advisors, as well as regulatory policies of policy authorities are of utmost importance.