US financial markets staged a huge flip flop on the back of the surprise win for Donald Trump in the US Presidential election.

Wall Street stocks rebounded strongly, the US dollar regained lost ground and US treasury yields firmed to eight-month highs.

As the evening progressed and the possibility of a Trump victory grew, US S&P stock futures plunged by 5 per cent or "limit down" - the maximum decline permitted before trading curbs kick. But later in the night, futures trading reversed, the index putting on a 1 per cent gain.

Likewise the US dollar was sold down sharply against the yen and several other currencies, only to erase its losses later in the night.


In US-10 year bonds - the bellwether instrument for borrowing costs - the yield shot up to 2.06 per cent from 1.7 per cent, reflecting expectations of higher inflation and the increased likelihood of a rate hike from the US Federal Reserve in December.

"We have had a massive flip flop - something that we don't see very often," Imre Speizer, senior markets strategist at Westpac, said.

"It was probably on a quick assessment that his policies were probably going to be good for growth," he said.

The New Zealand dollar traded at US72.70c, down from US72.80c last late on Wednesday night, The currency had traded at around US74c on Wednesday morning as markets then had priced in a Clinton victory.

By late in the US share trading session, the Dow Jones industrial average was up 155.59 points, or 0.85 percent, to 18,488.33 and the S&P 500 had gained 14.36 points, or 0.67 percent, to 2,153.92.

Speizer added that Trump's moderate acceptance speech may have had an influence on markets.

"The crazy Trump did not not turn up and, instead, we had a more measured Trump, so that might have had a calming effect," he said.

ANZ, in a commentary, said: "What a day. Volatility is certainly back."

Later this morning, the Reserve Bank will issue its review of the official cash rate at 9 am. Market expectations are for the bank cut its rate by quarter of a percentage point to 1.75 per cent.