The investment fund manager, AMP Capital, says it expects the New Zealand dollar to stay above US80 cents for some time to come.
Head of investment strategy Keith Poore says the dollar is over-valued and should be in the US70 cents.
Mr Poore says a sharp rise in the New Zealand current account deficit could prompt investors to withdraw their money, resulting in a fall in the currency.
He says while the latest round of quantitative easing by the US Federal Reserve lowers the American currency, it raises others, and on top of that, commodity prices rise too.
AMP Capital is continuing to invest heavily in stocks, both New Zealand and overseas, saying shares are well-priced in an environment awash with money being injected by central banks to boost weak economies.
The fund manager's balanced fund rose 5.6% in the three months to September, with a stronger equity performance being curbed by lower fixed income returns.
Meanwhile, AMP Capital lowered its forecast of global growth to 3% this year, with a modest improvement next year, driven by emerging markets like China.