Financial data terminal Refinitiv Eikon was hit by a “major incident” this morning as investors were unable to log in ahead of the London market opening.
The problem began shortly before 5am and prevented worldwide user from accessing the data hub, the Financial Times reported.
The company apologised to users and said it was working to resolve the problems as soon as possible.
It comes after stock markets sank into the red yesterday as China retaliated against US President Donald Trump by announcing tariffs on $60bn (£46.3bn) of American goods.
But ahead of London’s market opening this morning, investors were blocked from accessing Refinitiv Eikon’s platform.
“The major incident management process is being managed at the highest level to aid service restoration,” the alert said.
It added that customers were “experiencing intermittent login disruptions.”
The terminal is used by news organisations, investors and traders around the world to monitor markets.
In January last year, a consortium led by US private equity firm Blackstone bought 55 per cent of the Thomson Reuters Financial & Risk business, including the Eikon data platform, renaming the company Refinitiv.
A spokesperson for the company said: "Some Eikon and FX Trading users are experiencing login difficulties.
"We fully appreciate how critical these systems are to our customers and are actively working to resolve the situation as soon as possible.
We apologise for the inconvenience caused."