The purpose of this study is to analyse the methodological aspect of the relationship between the fundamental economic categories of «competition» and «money» throughout the twentieth century. The author polemises with the position of Alfred Marshall and Friedrich von Hayek on Gresham’s law as a specific form of monetary competition. The main results of the study include the positioning of the Russian Central Bank’s digital rouble as a digital form of the state treasury bill, which allows, in the author’s opinion, to correctly describe the specifics of competition in the field of digital currency. The digital rouble or digital treasury note is the highest but digital form of fiduciary money issued by the state, represented by the Central Bank. The digital rouble is not credit money but fiat money, although the paper banknote (cash) combined and still combines fiat and credit money. The digital rouble (Fiducia) on the Central Bank’s IT platform is theoretically and technically capable of replacing both paper cash (Fiducia) and digital non-cash (Fiat), as it is a version of a form of national currency that combines the properties of cash and noncash roubles and performs the functions of money as a measure of value, means of saving and means of payment. At the same time a Bitcoin is a return to commodity money, only in digital form. Bitcoin is highly competitive and capable to replace CBDC in all its versions.