#EthereumSecurityInitiative Bitcoin (abbreviation: BTC; symbol: ₿) is the first decentralized cryptocurrency. Based on the ideology of free markets, bitcoin was created in 2008 when an unknown entity published a white paper under the pseudonym Satoshi Nakamoto. The use of bitcoin as a currency began in 2009, with the release of its open-source implementation. In 2021, El Salvador adopted it as legal tender. It is largely viewed as an investment and has been described by some scholars as an economy.