2021 Bitcoin price chart. BTC/USD graph

Bitcoin (BTC) is an open source cryptocurrency, first released on January 3, 2009 by an unknown person behind the nickname Satoshi Nakamoto.
US Dollar (USD, $) is currency of United States, American Samoa (AS), Barbados (BB) (as well as Barbados Dollar), Bermuda (BM) (as well as Bermudian Dollar), British Indian Ocean Territory (IO) (also uses GBP), British Virgin Islands (VG), Caribbean Netherlands (BQ - Bonaire, Sint Eustatius and Saba), Ecuador (EC), El Salvador (SV), Guam (GU), Haiti (HT), Marshall Islands (MH), Federated States of Micronesia (FM), Northern Mariana Islands (MP), Palau (PW), Panama (PA) (as well as Panamanian Balboa), Puerto Rico (PR), Timor-Leste (TL), Turks and Caicos Islands (TC), U.S. Virgin Islands (VI), United States Minor Outlying Islands. Its fractional unit is Cent, 1 USD = 100 Cent(s).