The value of the most popular cryptocurrency, bitcoin, grows on Wednesday evening, exceeding the maximum level of December 2017 ($ 20,042) and updating a new all-time high at $ 20,535. Bitcoin, like other cryptocurrencies, has risen sharply since October. Digital currencies are rising in value amid optimism in global markets and expectations that the Covid-19 pandemic will be brought under control thanks to the emergence of vaccines against coronavirus infection. Additional support for Bitcoin is provided by a sharp weakening of the US dollar in the world market.