Bloomberg’s computer terminals, used ubiquitously in finance, went offline on Friday morning in London, derailing the day’s trading.

City slickers across the world took to Twitter to report that their computers were displaying a "connection lost" message, with systems having been offline for an hour at the time of writing.

John Ashbourne, Africa economist at Capital Economics, quipped: "If markets move, but there is no Bloomberg Machine operational to report it, does it make a sound?"

Financial exchanges were forced to move to Reuters’ platform to enact trade, though some staff tweeted that the outage was as a good an excuse as any to start the weekend early.

Contacted for comment by the press, Bloomberg confirmed the problem and said the company was working to fix it as quickly as possible.

It is unknown at present whether the outage was caused by a technical flaw or whether the network has been attacked.