Nigel Farage said market moves suggested 'Brexit may be happening again'
World stock markets have plunged as investors face up to a the possibility of a shock US election win by Donald Trump.
Japan's Nikkei slumped by 6% and in Hong Kong, the Hang Seng was off by 3%.
The US dollar also sank while the Mexican peso plummeted by 13% to a record low.
Investments seen as safe havens such as government bonds and gold, as well as the Japanese yen, turned higher as Mr Trump won key states.
In London, the futures market fell nearly 5% ahead of the stock market opening at 8am.
Sterling was up by a cent against the US dollar at $1.25 but lost a cent against the euro.
Oil was down, with a barrel of Brent crude falling below $45, a three-month low.
In Tokyo, the Japanese government and central bank were preparing to meet for crisis talks.
Markets had been expecting a victory for Hillary Clinton and many fear a Trump White House would up-end the global political order.
Stocks have seen a rollercoaster ride over the last week with sharp falls as Mrs Clinton came under pressure over an FBI investigation followed by rallies when the ending of the probe had appeared to tip the scales in her favour.
Election day saw tentative gains as investors waited anxiously on the result - but as voting projections swung in Mr Trump's favour trading turned volatile.
Early in the night, UKIP's Nigel Farage took to Twitter to compare the surprise results coming in from the US to the shock Brexit vote earlier this year:
Market moves suggest Brexit may be happening again.— Nigel Farage (@Nigel_Farage) November 9, 2016