The purpose of the study was to investigate on Market risk, Firms’ size and financial performance, Reality or illusion in microfinance institution. The study employed positivism philosophy and used explanatory non–experimental research designs. The targeted population was all the thirteen registered Deposit Taking microfinance institutions in Kenya and census approach was used. The study used secondary data which was collected from MFIs annual audited financial reports for the period between 2014 and 2018 using data collection instruments. The study was anchored on two theories namely Dynamic Capabilities theory and Modern Portfolio Theory. Diagnostic tests were applied to test on multicollinearity, autocorrelation, heteroscedasticity, normality test, and stationarity. Panel data multiple regression analysis was used to analyze the collected data and the results presented using figures and tables. The results indicated that firm’s size has a significant moderating effect on the relationship between market risk and financial performance of microfinance institutions. The study recommended that the CEOs of microfinance Institution should employ mechanism of identifying the optimal firm size that organization needs to operate in to achieve better financial performance.The purpose of the study was to investigate on Market risk, Firms’ size and financial performance, Reality or illusion in microfinance institution. The study employed positivism philosophy and used explanatory non–experimental research designs. The targeted population was all the thirteen registered Deposit Taking microfinance institutions in Kenya and census approach was used. The study used secondary data which was collected from MFIs annual audited financial reports for the period between 2014 and 2018 using data collection instruments. The study was anchored on two theories namely Dynamic Capabilities theory and Modern Portfolio Theory. Diagnostic tests were applied to test on multicollinearity, autocorrelation, heteroscedasticity, normality test, and stationarity. Panel data multiple regression analysis was used to analyze the collected data and the results presented using figures and tables. The results indicated that firm’s size has a significant moderating effect on the relationship between market risk and financial performance of microfinance institutions. The study recommended that the CEOs of microfinance Institution should employ mechanism of identifying the optimal firm size that organization needs to operate in to achieve better financial performance.