$BTC It is the symbol for Bitcoin, the first cryptocurrency launched in 2009. It is decentralized, meaning it is not controlled by any government or central bank, and relies on blockchain technology to secure and record transactions. Some use it as a means of payment, while others consider it an investment tool. Its maximum issuance limit is 21 million coins, making it relatively rare. It is known for its high price volatility and its influence on the cryptocurrency market.