The pound rose to a three-and-a-half year high versus the euro and the highest in more than a year versus the dollar after exit polls suggested a win for the Conservatives, which should help ensure the UK's smooth exit from the European Union.
The Chinese yuan rose in offshore trade and the Japanese yen fell after a source told Reuters that the United States and China have agreed some tariff reductions and a delay on tariffs set to go effect on Dec. 15.
The early results suggest the election will relieve almost four years of uncertainty about when Brexit would take place, which should be supportive of the pound.
A successful scaling back of trade tension would relieve one major headwind to economic growth, which suggests lower demand for the safe-haven yen. Avoiding new tariffs should also be a boost to China's slowing economy, which should draw more investors to the yuan.
"We've already seen a strong reaction in the pound from the exit poll," said Michael McCarthy, chief market strategist at CMC Markets in Sydney.
"We also see a rise in stock futures in reaction to two very important pieces of news for markets. This should support global growth. The yuan can also go higher, but it depends on how much dollar strength we get."
Against the euro, sterling rose around 2 percent to as high as 82.80 pence, the highest since July 2016, which is shortly after the Brexit referendum that hammered the currency.
The pound surged by 2.2 percent to $1.3474, reaching the highest since May 2018.
The pound plunged more than 10 percent in the immediate aftermath of Britain's vote to leave the European Union in June 2016, while $2 trillion was wiped off world markets.
The exit poll, which suggested UK Prime Minister Boris Johnson would get a majority of 86 - the largest of any Conservative leader since Margaret Thatcher won in the 1980s - should empower him to deliver Brexit on Jan 31.
Official results will be declared over the next seven hours.
Even if Brexit is completed on Jan 31, there is still some uncertainty because Britain will then enter a transition period during which it will negotiate a new relationship with the remaining 27 EU states.
In the offshore market, the Chinese yuan rose 0.33 percent to 6.9273 per dollar, after surging on Thursday to the highest since Aug 1 due to relief about a resolution to trade friction.
As part of the trade deal, China has also agreed to purchase $50 billion of U.S. agricultural goods next year, sources familiar with the talks told Reuters.
The yuan rallied and the yen fell late on Thursday after Bloomberg News reported that U.S. President Donald Trump signed off on a trade deal with China that will delay a new round of tariffs scheduled for Dec. 15.
A trade dispute between the United States and China over Chinese trading practices that Washington says are unfair has dragged on for almost two years, making the stand off the biggest risk to the global economy.
Against the dollar, the yen fell to 109.595, the weakest since Dec 2.