$BTC Bitcoin (BTC) is a decentralized digital currency, operating on a peer-to-peer network without central bank control. Created in 2009 by Satoshi Nakamoto, it uses cryptography to secure transactions recorded on a public ledger called the blockchain. New bitcoins are "mined" by computers solving complex problems. It functions as both a medium of exchange and a store of value, and its limited supply of 21 million units makes it a unique asset.