Bitcoin ploughed past $15,000 to a fresh record on Thursday, triggering a warning the cryptocurrency was "like a charging train with no brakes" and prompting fresh concern about its looming launch on mainstream markets.

It struck a new high of $15,242.99 around 1030 GMT, according to Bloomberg News. 

The rally came just a day after the virtual currency, which has been used to buy everything from an ice cream to a pint of beer, hit the $12,000 mark for the first time, while it has soared more than 50 percent in value in just one week.

Bitcoin -- which came into being in 2009 as a bit of encrypted software and has no central bank backing it and no legal exchange rate -- has risen from a 2017 low of $752 in mid-January and surged dramatically in the past month.