Bitcoin

Hackers steal $70 million worth of bitcoin as price marches upward

Hackers steal $70 million worth of bitcoin as price marches upward

Bitcoin surged past $17,000 Thursday — and briefly hit $19,000 — as the frenzy surrounding the virtual currency escalated just days before it starts trading on major U.S. exchanges. Bitcoin has gained more than $5,000 in just the past two days.

At the same time, there are fresh concerns about the security of bitcoin and other virtual currencies after NiceHash, a company that mines bitcoins on behalf of customers, said it is investigating a breach that may have resulted in the theft of about $70 million worth of bitcoin.

Research company Coindesk said that a wallet address referred to by NiceHash users indicates that about 4,700 bitcoins had been stolen. NiceHash said it will...