In 2015,as part of the policy of foreign exchange liberalization,the People’s Bank of China（ PBo C） has introduced a new CFETS index to assess yuan（ CNY） against 13 national currencies of China’s major trading partners. Simultaneously, the PBo C estimates RMB exchange rate with the help of the Bank for International Settlements index（ BIS）,the SDR basket of currencies and the RMB against the US dollar index. An analysis of the dynamics of the CFETS and BIS indices on daily exchange rates against 13 national currencies showed a strong mutual relationship between them. However,the numerical values of these indices differ substantially,making it difficult to choose one of them and understand what these indexes measure. To overcome these difficulties,we use the approach of Robert Schiller who proposed to apply the "baskets" containing fixed amounts of national currencies to build "True Value of Money" indexes. By selecting the "basket" of minimum variability,we use it as a Stable Aggregated Currency（ SAC）,which allows evaluating the dynamics of the exchange value of the yuan at a CNY/SAC coefficient of exchange,which measures the rate of CNY in SAC units. Reset