The cryptocurrency created in 2009 that first reached a price near US$20,000 in December 2017 was Bitcoin.
Bitcoin was introduced by the pseudonymous developer or group Satoshi Nakamoto. Its software and white paper described a peer-to-peer payment system that could operate without a central bank, using a public blockchain to record transactions. The network’s first block was mined in January 2009.
Bitcoin’s price rose sharply during 2017 as public interest, exchange activity, and speculation expanded. On December 17, 2017, it reached roughly $19,783, although the exact peak varied by exchange and price index. It then fell rapidly, dropping below $14,000 by December 22.
The 2017 surge is sometimes described as Bitcoin reaching $20,000, but it did not land on exactly that figure in every market. The other options were created at different times: Litecoin launched in 2011, Dogecoin in 2013, and Ethereum in 2015.