Masoumeh Kheradpisheh, - Master of Financial Management
Masoumeh Honarimehr - Master of Economics,

This article examines the effect of behavioral biases in investment decisions. This appliedresearch is descriptive-survey type. The target population of the current research is all theinvestors of the Tehran Stock Exchange, therefore the current research population isunlimited and the sample size is ۳۸۴ people based on Cochran's formula, which wasselected using simple random sampling. are The data collection tool in this research is astandard questionnaire. Research data have been analyzed using SPSS and Lisrel software.In order to analyze the data, two sections of descriptive and inferential statistics have beenused. Analysis has been done. In the inferential statistics section, research hypotheses havebeen tested using multivariate linear regression. The research results indicate that; Thereliance error on investment decisions with a coefficient of ۵.۰۹% shows a positive andsignificant influence on investment decisions with a coefficient of ۳.۴۷%. The massbehavior variable has a negative and significant effect on investment decisions with acoefficient of ۵.۸۳%, and the overconfidence variable has no significant effect oninvestment decisions with a coefficient of ۱.۰۲%.

behavioral biases, investment decisions placed in one line.