[SYDNEY] Sterling suffered its most volatile session in living memory and hit its lowest level since the 1985 Plaza Accord as Britain voted to leave the European Union, triggering a rush into safe-havens such as the yen and the dollar.
The euro also dropped more than three per cent against the dollar while the Swiss franc firmed along with the yen, though the wild moves made traders wary of intervention by Group of Seven countries.
"The markets are in a panic after optimistic swings yesterday. People are selling the pound and anything that is close to it while buying assets that are remotely related to the pound as possible, such as US Treasuries and the yen," said Ayako Sera, market economist at Sumitomo Mitsui Trust Bank.
The pound fell more than 10 per cent to US$1.3300, its cheapest level since September 1985, when five major economies at the time agreed to weaken the dollar. At 0345 GMT, it was hovering at US$1.3509.
"It is wild," said Shane Oliver, head of investment strategy and chief economist at AMP Capital in Sydney.
"There is still a way to go yet," Mr Oliver added. "Even if the vote is to leave, there is a lot of water to go under the bridge before Britain actually leaves the EU. We don't know what sort of deal they are going to cut with the EU."
- For more coverage of the EU referendum, visit bt.sg/BrexiT
Against the yen, sterling ricocheted between 133.65 and 160.10 and was last at 136.11, down a massive 13.8 per cent on the day.
The euro rose 8 per cent to 82.86 pence, hitting its highest level in more than two years.
Yet the euro was under pressure against most other currencies as investors fret Brexit could spark anti-establishment movements in other European countries, some of which have already seen decline in traditional political parties.
The referendum results fanned worries that it could lead to further discontent among European integrations and rise towards nationalism or regionalism, with an election re-run planned in Spain on Sunday after an inconclusive election last December.
The euro fell 3.6 per cent against the dollar to US$1.0975 , a low last seen in March.
The plunge in European currencies lifted the dollar index 3 per cent, which, if sustained, would be its biggest daily gain since 1978.
The sharp moves raised worries that global policymakers may take action to support the pound.
"We need to be careful about intervention in such a case. I think there's more than enough excuse for G7 to intervene," said Koichi Yoshikawa, executive director of finance at Standard Chartered Bank.
As Brexit anxiety grew, so too has demand for the safe-haven yen, which jumped on the greenback and euro.
The greenback dropped to 99.00 yen, a fall of 6.7 per cent, before gaining a semblance of stability at 101.50 yen, the first time it fell below the 100 mark since late 2013.
The euro fell to as low as 109.50 yen for the first time since late 2012.
Japanese Finance Minister Taro Aso declined to comment when asked about the possibility of joint G7 intervention.
The safe-haven Swiss franc also gained against the euro, which fell to 1.0685 franc, its lowest since August.
The Australian dollar, often sold off in times of heightened market stress, fell more than 3.6 per cent to US$0.7346.
Emerging market currencies were also sold heavily. The South African rand fell over seven per cent while the Turkish lira fell more than 4 per cent.