Abstarct: Introduction: Financial literacy is one of the most important factors influencing investors' financial decisions; But in the meantime, individual and personality traits also play an important role in the decision-making process. In this regard, the present study aims to study and understand the behavior of investors to evaluate the impact of financial literacy on investment decisions with respect to the mediating role of the big-five model. Method: The statistical population of the study includes shareholders and traders of Tehran Stock Exchange and the statistical sample includes 386 people. A Likert scale questionnaire was used to collect data and Spss26 software was used for descxriptive statistics in the descxriptive statistics section and Smart PLS3 software in the inferential statistics section with a partial least squares approach. Findings: The results of the study show that financial literacy through the mediation of investors' receptivity has a negative effect on their financial decisions, but the characteristics of extraversion, conscientiousness, neuroticism and agreeing on the impact of financial literacy on investment decisions do not have a significant mediating effect. Conclusion: The trait of receptivity, which includes individual characteristics of curiosity, creativity, diversity and empiricism, can mediate the impact of financial literacy on investors' financial decisions..