Bitcoin was the first cryptocurrency created and is now the most traded and well-known. It was first launched in January 2009 by a computer programmer or group of programmers under the pseudonym Satoshi Nakamoto, whose actual identity has never been verified. 

A 2008 white paper by Bitcoin's mysterious creator originally revealed the blockchain system that would be the backbone of the cryptocurrency market. A blockchain is a digital ledger of transactions that is replicated and distributed across a network of computer systems to secure information.