Unusual fluctuations in return due to risk Fluctuations in specific returns of companies, which are mainly due to the actions of the company and independent of the general movement of the market. The main purpose of this study is to investigate the relationship between comparability of financial statements and unusual fluctuations in stock returns. Also, the moderating role of two variables of analysts' forecasting error and the quality of financial reporting as dimensions of the information environment on this relationship was examined. For this purpose, 76 companies for the years 1392 to 1398 were selected by screening. Two market models, Fama and French, were used to measure abnormal stock returns. The concept of difranco economic phenomena was also used to measure the comparability variable. Multivariate correlation and regression methods were used to test the hypotheses. The results showed that there is a significant relationship between the comparability of financial statements and unusual fluctuations in stock returns. The results also indicate that analysts' forecasting error can play a moderating role in the relationship between the comparability of financial statements and the reduction of abnormal fluctuations in stock returns. Finally, it was found that the quality of financial reporting can affect the relationship between the comparability of financial statements and unusual fluctuations in returns.