The FTSE 100 has lost more than one 10th of its value as global stock markets faced a rout in the face of Covid-19 fears.
London’s top index had lost more than 633 points on Thursday afternoon, or 10.8%, bringing it to the lowest point since 2012.
Almost £159 billion had been wiped off the stock exchange in only one day and is the worst intraday drop since the financial crisis in 2008.
With only minutes left until the markets closed, the FTSE also looked set for its worst daily trading since October 1987, and its third worst day in history.
It comes after the World Health Organisation upgraded the coronavirus outbreak to a pandemic, sending the index down by more than 300 points as it opened on Thursday morning.
On Thursday the European Central Bank failed to calm markets as it announced measures to tackle Covid-19’s impact on the economy, but did not change interest rates.
On Wednesday US President Donald Trump suspended travel from most of Europe to the US.
Spreadex analyst Connor Campbell said: “A horror show US open turned an already very bad day into the kind of session that could go down as historic, if for all the wrong reasons.
“It is hard to keep coming up with new metaphors for the scale of disaster facing the global markets.
“Equities are getting crushed under foot as investors flee to the fire exit, desperately scrambling about for safe havens that feel anything but.”
He added: “The ECB’s stimulus package seemingly only made matters worse.
“Withstanding the pressure to cut rates to a fresh record low, the central bank announced an 120 billion euro expansion to its ongoing quantitative easing programme, alongside new longer-term refinancing operations and cheap loans for banks to encourage lending to ’those affected most by the spread of the coronavirus’.”