Bitcoin firm hacked days before major US exchange opens

TOKYO (AP) — A bitcoin mining company in Slovenia has been hacked, for the possible theft of tens of millions of dollars, renewing questions about the security of the virtual currency just days before it is due to start trading on major U.S. exchanges.

NiceHash, a company that mines bitcoins on behalf of customers, said Thursday it is investigating a security breach and will stop operating for 24 hours while it verifies how many bitcoins were taken.

Research company Coindesk said that a wallet address referred to by NiceHash users indicates that about 4,700 bitcoins had been stolen. At Thursday's record price of about $14,000, that puts the value at almost $66 million.