On Friday morning Bloomberg terminals—the connective tissue of global finance—went dark. The issue began after 3:00 a.m. ET and affected deals worldwide, delaying the sale, for instance, of more than $4.5 billion in treasury notes by the United Kingdom’s Debt Management office.
Bloomberg LP, the company that sells the approximately $20,000 data analysis and market news portals called Bloomberg Professional, confirmed to CNBC Friday that its terminals were indeed unavailable across the globe. The company, which makes the overwhelming majority of its money on the more than 320,000 subscribers to its machines, said it is investigating the issue.
We are currently restoring service to those customers who were affected by today’s network issue and are investigating the cause.
— Bloomberg (@Bloomberg) April 17, 2015
Traders, who use the specialized computers in the day-to-day financial transactions, took to Twitter to air their complaints (you can read some of their best tweets here). Bloomberg’s chat tool, a popular communication service and feature of the terminals, was apparently unavailable for griping.
#bloombergdown putting batteries in my financial calculator
— Roni Green (@ronigreen) April 17, 2015
https://twitter.com/jamestitcomb/status/588975956687216640
One anonymous trader whose terminal reportedly experienced an outage for about an hour and a half told the New York Times that operations had ground to halt at his workplace: “You can’t do anything at all,” he said.
The same trader also told the newspaper that switching to a competitor’s terminal, such as the one offered by Thomson Reuters, was not an ideal option: “People are used to going through ‘Berg, and so it’s confusing for a lot of us who never use Reuters,” he reportedly said.
Meanwhile, a trader in Singapore told CNBC that his team had switched to a Reuters platform in the interim.
Others took alternative measures. A fixed income banker told the Wall Street Journal that he had resorted to using a phone to execute deals, which he described as feeling “incredibly ‘old fashioned.'”
By 4:30 a.m. ET, terminal service was restored for some banks. Four hours later, Bloomberg tweeted that the issue was all but resolved.
Service now restored to most customers following disruption to parts of our network. Making progress bringing the full network back online.
— Bloomberg (@Bloomberg) April 17, 2015
The outage is also apparently not the result of a cyber attack.
There is no indication at this point that this is anything other than an internal network issue.
— Bloomberg (@Bloomberg) April 17, 2015
Though Business Insider has reported a rumor that someone spilled a can of coke on a server somewhere, Fortune remains skeptical. (Revenge, perhaps, for former three-term New York City mayor Michael Bloomberg’s failed bid to outlaw big soda drinks? The former mayor recently returned to lead the company he founded in 1981.)
Read next: “The trouble at Bloomberg” by Fortune’s Peter Elkind.
[fortune-brightcove videoid=4174792045001]
