The last time bitcoin crossed the $18,000 mark was on December 19, 2017. Bitcoin accounts for approximately 66 percent of the entire global cryptocurrency market.
Bitcoin is a decentralized online currency that is not subject to a central bank or administrator, which has built-in value due to an artificial scarcity through its accumulation process known as 'mining'.
Bitcoin and the other digital currencies that have followed it have been hailed as alternatives to fiat money.