Utilising their investments, securities, and mutual funds can create significant advantages, especially for savers with information and time constraints. They can also offer opportunities for small investors to be part of larger-scale investments and to participate in well-diversified portfolios. The success of securities investment funds is often directly related to the performance of fund managers. Fund managers are expected to outperform the funds they manage regarding return and risk compared to the base stock market indices and similar funds. In this study, the performance evaluation of BIST 30 index equity mutual funds was carried out. In this way, both the performance of the funds relative to the base index has been analysed, and the opportunity to make a performance comparison among the funds has been provided. Beta Timing Ratio was used as the performance evaluation method. In this way, with the help of a risk-adjusted method, the performances of mutual funds during the upturns and downturns in the stock market were analysed together. As a result of the study, it was determined that the Beta Timing Ratio values of all mutual funds within the scope of the study were well above the minimum acceptable value.