Global Currencies Volatile in Asia as Investors Await 'Brexit' Results

Global currencies were volatile early in Asia ahead of the open of most major markets here on Friday, as investors stayed wary about whether the U.K. had voted to stay or leave the European Union.

Polls in the U.K. have closed, and results of the voting are trickling in, with the final tally expected in the next few hours.

The British pound, which jumped to its highest levels of the year after the polls closed, soon tumbled after a key district in the northeast of the country voted in favor of leaving the EU.

The currency has been in a spin, as traders try to position themselves according to opinion polls leading up to the vote as well as on speculation after the polls closed. The pound was down 2.3% at $1.45 in early Asian hours.

The Japanese yen, considered a haven for investors, gained 1.1% against the U.S. dollar early in Asia.

Still, with global equity markets having rallied overnight, stocks in New Zealand were up 0.4%, setting a positive tone for the Asian equity trading day.

"I think we're going to see some rallying across Asian markets," said Daisuke Nomoto, head of Japanese equities at Columbia Threadneedle Investment. He said he still believed there was "a more than 50% of chance that the U.K. would remain."

An opinion poll by YouGov PLC, published just after the close of voting, showed support for the U.K. remaining in the EU at 52% and the exit camp at 48%.

Overnight U.S. stocks rose, with the Dow industrials up 1.3% and the S&P 500 gaining 1.3%.

European stocks surged, with many indexes posting their fifth consecutive session of gains. The Stoxx Europe 600 climbed 1.5%, London's FTSE 100 gained 1.2%, and major indexes in Germany, France and Spain each finished up about 2%.

"Obviously there was a bit of a rally in offshore markets last night, so some investors might try and do some buying early on, but I think overall investors will pretty much remain on the sideline until we've got a bit more certainty around the final result," said Grant Williamson, a New Zealand-based investment adviser at Hamilton Hindin Greene.

Still, investors were on edge.

Like many fund managers, Columbia's Mr. Nomoto said he didn't rule out the potential for the U.K. to vote to leave the EU. He said his investment team didn't make any one-way bets.

"What we did was try to reduce the volatility of the portfolio," Mr. Nomoto said.

Risk currencies like the Australian dollar were stepping back, recently down 1.1% against the U.S. dollar at $0.7528.

The global crude benchmark Brent was up 0.5% at $51.14 a barrel, while its U.S. counterpart, West Texas Intermediate, was up 0.49% at $49.37 for August deliveries.

Adam Cole, the head of G-10 FX strategy at RBC Capital Markets in London, said a vote to exit the EU would be a "bolt from the blue" but added the degree of confidence markets for a stay vote was unwarranted. "I wouldn't have the degree of confidence that the markets seem to.... If the vote is to remain, I would still be a buyer, but I wouldn't have very ambitious targets," he said.

Kate Geenty contributed to this article.

Write to James Glynn at