The article introduces a classification of research programs related to the cryptocurrency market. Each of them is surveyed, with the emphasis placed on the most recent studies. Despite the presence of market frictions, its informational efficiency tends to increase, thereby making it more comparable with the conventional financial markets. In particular, cryptocurrencies can be used for portfolio diversification. Yet, they can hardly compete with fiat money. Currently, central banks are only interested in examining and adopting some of the cryptocurrency features to create their own wholesale digital currencies.