In mid-1391, sanctions and reduced foreign exchange earnings from oil exports, government regulation of the currency market and exchange rates exchange got impossible and alternative exchange rate was replaced with reference exchange rate, Followed by, Rials Equivalent of corporate foreign exchange facilities Multi-fold increased and This difference should be accounted in the foreign currency loss for that period. In this regard, the Audit Organization in August 1392 by amending the Accounting Standard no.16 with the terms of position gave the license of transferring foreign losses in the foreign currency financing facilities granted to the cost of the assets created. This study investigated that investors, by applying the amended standard, consider reporting increased profits are regarded as good news in the market or consider it as income smoothing that predicting firms Lack of future cash and is not a positive signal. Therefore, the mean percentage change in stock value and volume of firms in the sample before and after the amendment of the accounting standard No. 16 and performing Non-parametric Wilcoxon rank test, was found: At intervals of 21 and 30 days, the value of stock transactions after the modified standard "The effects of changes in exchange rates" has decreased than before and at intervals of 21, 30 and 50 days, the volume of stock transactions after the modified standard "The effects of changes in exchange rates" has decreased than before.