Bitcoin rose as much as 4% on Thursday to top $37,000 and has more than quadrupled in the past year, according to a composite of prices compiled by Bloomberg. It accounts for about two-thirds of cryptocurrency market value, followed by Ether on about 14%. Ether is up 62% so far this year.
Digital coins are jumping in a world awash with fiscal and monetary stimulus, even as some commentators fear an inevitable bust and others question the basic integrity of crypto markets. Proponents of Bitcoin argue it offers a hedge against dollar weakness and the risk of faster inflation, a bit like gold, while critics decry the intellectual soundness of comparing the two assets.

Active Bitcoin accounts are nearing their all-time high levels of late 2017, according to researcher Flipside Crypto -- possibly a sign that some holders are planning to sell. Fewer than 2% of accounts hold 95% of Bitcoin supply, so a few big trades can impact prices. The last big Bitcoin boom began imploding in late 2017.
Some traders pointed to JPMorgan Chase & Co.’s long-term Bitcoin price forecast of $146,000 as possibly fueling the rally. Others said sentiment was boosted by a U.S. regulatory update that allows a class of less volatile coins to be used by banks for payments.

Coaxial cables connect to a computer server unit inside a communications room at an office in London, U.K., on Monday, May 15, 2017. Governments and companies around the world began to gain the upper hand against the first wave of an unrivaled global cyberattack, even as the assault was poised to continue claiming victims this week. Photographer: Chris Ratcliffe/Bloomberg