World Bulletin / News Desk

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.

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.

The increased interest has been driven by growing acceptance among traditional investors of an innovation once considered the preserve of computer nerds and financial experts. 

But some, including the US Federal Reserve, have warned against dabbling in bitcoin as it could threaten financial stability, and fears of a bubble have increased as the price has soared.

"Bitcoin now seems like a charging train with no brakes," said Shane Chanel, from Sydney-based ASR Wealth Advisers. "There is an unfathomable amount of new participants piling into the cryptocurrency market."

But he warned: "Once the hype slows down, we will most certainly see some sort of correction."