Bitcoin rallied past $US16,000 ($20,705) on Tuesday US time as traders of the world's biggest digital currency sought to draw a line under its rollercoaster five-day slump.

The tokens rose 16 per cent to as much as $US16,132.09, the biggest gain on a closing basis in more than two weeks and the first in six days. It traded higher by 14 per cent to $US15,659.9 as of 1.36pm in New York. Rival currencies litecoin and ethereum were up 4.4 per cent and 2.6 per cent, respectively, according to data compiled by Bloomberg.

High trading volumes at Coinbase, one of the biggest exchanges, forced the company to issue a warning on its website that transactions for bitcoin and ether may be delayed by several hours.

The gains will be a welcome relief for crypto bulls, after bitcoin declined 26 per cent in the five days through Monday in what was seen as a big test for the nascent digital currency industry. The advance suggests that, even as financial authorities issue warnings about the risks of a bubble in the asset class, investor interest remains intact, at least for now.