LOS ANGELES (BLOOMBERG) - Bitcoin is already having a bad year.

For the first time since 2015, the cryptocurrency began a new year by declining, extending its slide from a record US$19,511 reached on Dec 18.

The virtual coin fell to US$13,624.56 as of 5 pm in New York on Monday, down 4.8 per cent from Friday, according to data compiled by Bloomberg. That's also a drop from the US$14,156 it hit on Sunday, according to coinmarketcap.com, which tracks daily prices.

The cryptocurrency fluctuated in Asian trading on Tuesday, trading 1.9 per cent lower as of 3:22pm in Hong Kong.

Bitcoin got off to a much stronger start last year, and then kept that momentum going, helping to create a global frenzy for cryptocurrencies. It rose 3.6 per cent on the first day of 2017 to US$998, data from coinmarketcap.com show. It ended the year up more than 1,300 per cent.

That rally drew a growing number of competitors and last month brought bitcoin to Wall Street in the form of futures contracts. It reached the Dec 18 peak hours after CME Group debuted its derivatives agreements, which some traders said would encourage short position-taking.