Bitcoin's relentless rise continued on Thursday, shooting past the $15,000 mark and adding to fears of a dangerous market bubble.
According to Coindesk, the cryptocurrency touched an all-time high of $15,058.30 before paring gains to trade at $14,971.88 in early afternoon trading.
Despite its value climbing nearly 1,500% since the start of the year, financial heavyweights are divided over the digital currency's significance.
JP Morgan boss Jamie Dimon has branded Bitcoin a "fraud", while Christine Lagarde of the International Monetary Fund said "it may not be wise to dismiss virtual currencies".
Craig Erlam, OANDA senior market analyst, said: "The cryptocurrency has undoubtedly come on leaps and bounds this year but it's difficult to see anything move as Bitcoin has and not fear a devastating bubble bursting.
"I don't think it's a coincidence that Bitcoin has been making headlines over the last week or so, during which time it's risen another $5,000, or 50%.
"If speculation is playing as big a role in the latest moves as some expect, then very interesting times may lie ahead."
The Treasury has announced plans for closer scrutiny of the cryptocurrency as part of EU-wide plans that will require online platforms that trade in Bitcoin to carry out due diligence on customers and report suspicious transactions.
But that has not curbed excitement over its emerging investment opportunities.
US regulators have given the green light for three American exchanges to offer futures trading in the cryptocurrency, including the Chicago Mercantile Exchange (CME) and the CBOE Futures Exchange (CFE).
Nasdaq is also considering offering Bitcoin futures in early 2018.
UK app Revolut said it will start offering cryptocurrency trading this week, with customers able to buy and exchange Bitcoin, Litecoin and Ether from Thursday.