Bloomberg's chat function crashed
Instant Bloomberg - as it is officially known - is touted by the company as the first ever social network, and is used every day by thousands of traders, analysts, and hedge funders across the globe to communicate with one another.
More than 315,000 people use Bloomberg terminals globally, so when any function goes down, it is a major issue for financial markets.
Writing just after 3.00 p.m. BST (10.00 a.m. ET) Robin Wigglesworth of the Financial Times cited a person familiar with the outage saying that the crash is an "internal issue" and that "service is being restored."
According to several Twitter users, the service has now been restored, although it is not clear if some terminals are still affected.
Bloomberg did not immediately respond to a request for comment from Business Insider.
The last major outage of Bloomberg terminals came in April last year, when machines around the globe suffered a two hour long crash which led to major disruptions for traders.