The New Zealand dollar has been supported by investors borrowing in low-interest rate economies in the US, Europe and Japan and investing in higher-yielding New Zealand bonds.
"People are speculating that trend is at an end," Tuck said.
Still, the kiwi will likely find support should separate reports out today show strong New Zealand retail sales and that overseas demand for New Zealand bonds continued in April.
Retail sales volumes are forecast to have edged up 0.8 per cent in the first quarter, according to a Reuters survey of eight economists. ANZ expects a 1 per cent gain.
"That may arrest the New Zealand dollar decline," Tuck said.
Weaker than expected data would add to the downward momentum, he said.
Traders will be watching further US data out this week for signs of a sustained improvement in that economy. That includes reports on April industrial production, a speech by Federal Reserve Bank of Philadelphia President Charles Plosser, and reports on inflation and household debt.
The New Zealand dollar fell against is Australian counterpart to 82.78 Australian cents from 83.07 cents at 5pm yesterday. The kiwi dropped to 83.94 yen from 84.49 yen, and slid to 63.49 Euro from 63.99 Euro. It weakened to 53.85 British pence from 54.09 pence.