Exporters are calling for firm action from the Reserve Bank and the Government to push the dollar back to levels considered realistic.
Craigs Investment Partners broker Chris Timms said as investors around the world had become more open to investment risk, the transtasman currencies had been in demand.
After Japanese investors had seen the value of their property fall by up to 75%, their sharemarket investments fall by more than that, and given they were getting 0.1% on Japanese bank deposits, they had started looking for better returns.
"When they buy a New Zealand Government bond for 4.5%, they think all their Christmases have come at once."
To buy a bond, they needed to convert the yen into New Zealand currency, creating a demand and helping keep the dollar high, Mr Timms said.
The United States dollar was under pressure yesterday, keeping around a 14-month low against a basket of currencies while investors turned to growth-linked currencies, anticipating Chinese data due out soon.
The British pound rose immediately after minutes from a Bank of England meeting suggested officials were not ready to expand an emergency asset buying programme.
Analysts said that suggested central banks outside the US were considering winding down programmes that had flooded their economies with money.
If the US Federal Reserve did not follow suit and held interest rates at record lows, that would diminish investor desire to hold dollars, the analysts said.
The Fed has extended more than $US2 trillion ($NZ2.65 trillion) of credit to the financial system and chairman Ben Bernanke has previously said tightening monetary policy in the US is some way off.
Part of the reason the US dollar is hobbling along is that investors think the Fed is handcuffed until the labour market stops contracting.
Mr Timms said the the fate of New Zealand dollar had been very closely aligned to the performance of the US sharemarket.
As the US economic growth returned, and outstripped other regions, the US dollar would rise and the New Zealand dollar would fall, he said.
