The occurrence of economic crises in the past shows how important the role of supervisory institutions in the independent financial services sector is. The establishment of Supervisory and Regulatory Institutions Financial service institutions in Indonesia was launched based on the mandate of Law Number 21 of 2011 concerning the Financial Services Authority (FSA). FSA is an independent entity that is free from interference from other parties, with the responsibility, duties, and authority to regulate and supervise financial service institutions in an integrated manner. However, after more than ten years of operation, various cases still occur in financial services, especially in the capital market, which consequently greatly harms investors. This research aims to evaluate the implementation of supervision of capital market financial services by the OJK and find out how this can improve legal protection for investors. The research method used is descriptive analysis with a normative juridical approach with qualitative analysis. Focuses on legislation, principles, and legal theories that regulate capital market supervision. This research found that although OJK is an independent institution, OJK's independence is not absolute. Apart from that, OJK as the only supervisory institution means that supervision by OJK is inadequate, and investors are less protected.