The New Zealand dollar was little changed at the end of a wild rollercoaster day driven by a "flash crash" on global currency markets that was probably caused by computer-driven trading in thin, holiday-dampened activity.

Meanwhile, overall negative sentiment was reinforced by a string bad news that sent investors fleeing to safe havens such as the US dollar.

The kiwi was trading at 66.24 US cents at 5pm from a low at 65.88 earlier in the day, but little changed from 66.27 at 8.20am. The currency had reached a high of 67.50 in New York overnight. The trade-weighted index eased to 72.61 points from 72.87 this morning.

The Japanese yen was another beneficiary of the flight to safety, the New Zealand dollar trading at 70.98 from 72.42.

Advertisement

"All the excitement came this morning and it was predominantly in currency markets," said Mike Shirley, a senior trader at Kiwibank.

"It looks to have been a 'flash crash' driven by computer trading – it's a Japanese holiday so they're out," Shirley says.

"There was a lot going on at the time, but it wasn't enough to have caused what happened – it's all very much a risk-off theme."

The negative news included an announcement from Apple Inc. which downgraded its sales forecast and blamed weaker sales in China, adding to concerns that the global economy generally and the Chinese economy in particular are slowing.

A meeting in Washington between President Donald Trump and senior congressional and senate leaders from both political parties on reopening a large swathe of the US government ended in a continued stalemate.

As the federal shutdown headed towards the end of its second week, and a day before the Democrats take control of the lower House, Trump reportedly said he couldn't accept the Democrats' offer because he "would look foolish if I did that."

Sabre-rattling over Taiwan by Chinese President-for-Life Xi Jinping didn't help. He urged the people of Taiwan to accept that it "must and will be" reunited with China and said that China reserves the right to use force.

Taiwan is self-governed but has never formally declared independence from mainland China.

The ECB's decision to appoint three temporary administrators to Italy's Banca Carige after most of its directors resigned was yet another negative and the market remains nervous ahead of Britain's scheduled mid-month parliamentary vote on Prime Minister Theresa May's Brexit deal.

May used her New Year's message to urge Parliament to back her Brexit deal, and Downing Street officials confirmed that May has been seeking further concessions from fellow European leaders over the Christmas period.

The alternative would be a "hard Brexit" in March, assuming Britain does actually leave the European Union.

Against the British pound, the kiwi is trading at 52.77 pence from 52.74, at 58.29 euro from 58.63, and at 4.555 Chinese yuan from 4.5631.

In interest rate markets, the two-year swap rate rose to 1.9324 percent from 1.8925 while the 10-year rate rose to 2.554 percent from 2.515.