Bitcoin continued to surprise investors and analysts as the cryptocurrency blasted through $11,000 a coin to all-time high of $11,395 on Thursday. A 15 percent increase from Wednesday’s peak of $10,787.99.

So far, the coin has gained more than 1,000 percent in 2017 even as some experts called for caution and proper regulation of the digital currency.

According to Neil Wilson, a senior market analyst at CFD provider ETX Capital, Bitcoin rise as “a massive speculative bubble”.

“It’s hard to say precisely where we are in the curve, but the shape of the chart is parabolic and this sort of thing never, ever lasts. So far it’s following the playbook for a speculative bubble to the letter,” he added.

The highly volatile cryptocurrency has since lost about $1,000 of its value to $10,228.

However, the recent upsurge is in line with experts’ projection that the virtual currency still has more room to go. For instance, Goldman Sachs technical analyst Sheba Jafari called current rally in early November, saying; “Given that this is just a third of five waves up, the implications are that Bitcoin has potential to run further over time.”  This was when the coin was trading below $8,000.

Meanwhile, a federal judge in San Francisco ruled on Wednesday that Coinbase, one of the biggest Bitcoin exchanges, must provide IRS details of users who transact more than $20,000 a year through its platform.

This was after the IRS noticed the number of tax returns claiming gains from digital currency wasn’t in line with the rise in digital currencies like Bitcoin as a new investment vehicle.