Bitcoin, invented in 2008 by an unknown person (or people) and first used in 2009, is the world's first and best-known cryptocurrency. It reached its highest value of around USD 68,700 (over CZK 1.5 million) in November 2021. Today, BTC 1 is worth USD 26,700 and Bitcoin has a market capitalization (total value) of over USD 500 billion. Around 92 percent – or 19.3 million – of all existing bitcoins have been mined.