Abstarct: This study addresses the role of brand deterrence on reducing the value of companies in the face of short-term market shocks. This research is an applied one in terms of its purpose and is in the category of causal and post-event research baxsed on objective data. In this study, the statistical population of the study includes all companies listed on the Tehran Stock Exchange during the years 2009 to 2018. This statistical population includes all companies that were selected through the removal method for sampling and finally a sample of 94 companies with 11,280 monthly data was selected. After collecting the required data for the research, Excel software was used to calculate and prepare the variables. Eviews software was used to analyze the research data. According to the research hypotheses and considering the two dimensions of time and data collection interval, to test the hypotheses, a Panel regression model has been considered and the research variables are classified into three categories of dependent, independent and control variables. The dependent variable is related to the stock price logarithm and estimated brand value during the year, the independent variable is associated with the total stock index, market shock (shock due to trading volume and shock due to the index) and estimated brand value (using Damodaran average profit model). The control variables include net profit, official value of equity and the natural logarithm of the value of daily equity. Findings showed that positive brand changes have a positive effect on stock prices and negative brand changes have a negative effect on stock prices and the intensity of negative changes is more; In addition, positive changes in the stock market have a non-linear positive effect on stock prices and negative changes in the stock market also have a non-linear negative effect on stock prices. The other results of this study indicate that market shocks resulting from trading volume have a negative impact on company value and shocks resulting from the index have a negative impact on company value. Finally, the most significant finding of this study indicates that market shocks have a less negative effect on the value of companies with a strong brand than the value of companies with a weak brand.