Warning signs about another bitcoin exchange

San Francisco

AS the price of bitcoin has soared, the virtual currency has edged towards the mainstream.

Square, the fast-growing payments company run by Twitter co-founder Jack Dorsey, has begun selling bitcoins to ordinary consumers, and the Chicago Mercantile Exchange will soon allow banks to trade on the value of bitcoin. But if you want to see where the price of bitcoin is actually determined in round-the-clock bidding, you have to go to a number of unregulated exchanges that often fly in the face of US and European laws.