Bitcoin (also known as BTC or XBT) was the first ever decentralised cryptocurrency. This decentralisation is a defining feature of the currency and it means that it is not under the control of any central bank or regulatory authority. The creation (mining) of bitcoins is limited to 21 million units, with more than half that number having already been mined. Bitcoins can be traded on exchanges for fiat currencies (dollars, euros etc.) and for other cryptocurrencies. It can be used to pay for products and services, as well as for opening a bank account and receiving income in the form of interest. Moreover, the bitcoin has received official recognition as a means of payment in Japan. Bitcoin’s market cap is comparable to that of companies such as Delta Air Lines, CME Group and Ford Motor Company.