LONDON — Bitcoin hit a fresh all-time high on Thursday, passing the $5,000 mark in early-morning European trade.

UPDATE: Bitcoin has now passed above $5,500 per coin.

The cryptocurrency has held onto those gains into the early afternoon, with bitcoin trading up by close to 8.5% on the day, hitting a value of $5,223 by 12.20 p.m. BST (7.20 a.m. ET) as the chart below illustrates:

Bitcoin has seen its value increase by more than $750 a coin in the past week alone, with a rally that coincides with renewed interest in the currency from investment banks. The Wall Street Journal last week reported that Goldman Sachs was looking at setting up a bitcoin trading operation, and Morgan Stanley CEO James Gorman said recently that the cryptocurrency was "certainly more than just a fad."

The day's rise comes "as bulls returned to the market with a vengeance," according to Neil Wilson, a senior analyst at ETX Capital.

"Regulatory woes have subsided with reports indicating that China may be ready to allow trading again, albeit with tighter regulation," he added. "The prospect of Goldman Sachs trading Bitcoin is also driving buying as this might give it a toehold on Wall Street that could bring it into the mainstream and attract fresh inflows of capital."

The cryptocurrency's massive boom has its detractors, however, with Michael Novogratz, a former manager at the $72 billion investor Fortress, calling it "one of the great manias of all time" in an interview on CNBC earlier this week.

"It would not surprise me if, in the next six to 10 months, we're over $10,000," Novogratz told CNBC on Tuesday.

Also this week, a team of analysts led by Gautam Chhugani and Gaurav Jangale from the research house Bernstein said that bitcoin was still just a "censorship-resistant asset class," out of the reach of state control and yet to form a part of the system of settlement and credit that defines money.

"Fiat money is still the final form of settlement — governments still collect taxes in fiat money and salaries are still paid in fiat money," the team said in a note to clients on Wednesday.