Bitcoin starts on the huge CME exchange
Bitcoin has moved another step towards mainstream investing with the start of trading on the huge Chicago Mercantile Exchange financial futures market.
It comes as the value of the digital currency approached $20,000 on Sunday, before drifting below $19,000.
Last week, Chicago's CBOE exchange began Bitcoin futures trading - bets on a future price - but CME is far bigger.
On Sunday, the chairman of UBS bank and former Bundesbank head Axel Weber joined the chorus of Bitcoin warnings.
"Bitcoin is not money," he said in an interview, and urged regulators to intervene.
Bitcoin prices have surged this year: a single bitcoin stood at less than $1,000 in January and hit a record $19,783 on Sunday, according to Coindesk.
Analysts believe CME's entry into the Bitcoin market will generate more interest in the crypto-currency, possibly pushing the price higher.
Read more: