The New Zealand dollar soared two U.S. cents overnight mostly before it became clear that Slovakia would sign off on the European region's bailout fund.
The kiwi dollar was at 79.78 US dollars at 8am, up from 77.88 cents at 5pm yesterday. It made significant gains around 9pm local time last night.
Dan Bell, a senior dealer at HiFX, said the extremely aggressive move higher came in the first two hours of London trading and the Australian dollar made a similar move, helping it rise 3.5 percent from its lows yesterday.
The rallies in the trans-Tasman currencies were much greater than the rallies on equity markets they have been tracking, and they occurred before reports that Slovakian politicians had brokered a deal to sign off on the Euro-zone's European Financial Stability Fund.
"I think market positioning has played a big part in this. The market was extremely short kiwi and Aussie and someone wanted to get back in," he said, referring to the currencies colloquially.