The growth in cryptocurrency market capitalization was particularly vigorous in November-December 2017, with capitalization exceeding $650 billion on December 21, followed by a slight downward adjustment. The overall growth was driven by the increase in Bitcoin capitalization by approximately $220 billion, from $15.5 billion to $236.7 billion, with the substantial increase in altcoin capitalization by $374 billion, from $2.2 billion to $376.2 billion, accounting for the remaining growth. The total number of cryptocurrencies and digital assets on exchanges increased over the year from 617 to 1,335 (according to the data of coinmarketcap.com), i.e. they more than doubled. Due to the appearance of a large number of competitors (altcoins), the dominance of the main cryptocurrency (Bitcoin) fell considerably over the year, from 87.5% to 38.6%. Figures 2 and 3 show a breakdown of cryptocurrency market capitalization (USD billion) and dominance (%) at the start of 2017 and 2018.
https://www.coinspeaker.com/2018/01/04/cryptocurrency-ico-market-overview-2017/
