The New Zealand dollar jumped almost one cent on Thursday morning to reach its highest level against the US dollar in nearly 10 months.
The kiwi peaked at 66.3 US cents, before falling back to 65.95 cents by 8am on Thursday and to 65.9 by 12.30pm.
While the dollar also rose against other major currencies, Derek Rankin from Rankin Treasury Advisory Ltd says the currency's performance is almost entirely due to weakness in the US dollar.
He says America is "effectively printing money" at a significant rate as part of its its quantitative easing programme, weakening the US currency.
Mr Rankin expects to see the New Zealand dollar reach 70 US cents later this year.