Trading volumes hit a record high and around $2 trillion was wiped off global stocks after Britain surprised financial markets by voting to leave the European Union.

The pound collapsed to a three-decade low and the FTSE 100 plunged 8.7pc within minutes of the opening bell as traders endured the most treacherous rollercoaster ride since the height of the financial crisis in 2008.

An offering of more than £250bn to ease any squeeze in markets from Bank of England governor Mark Carney softened the Brexit blow, lifting London’s benchmark index from the doldrums.