Since the middle of this month, the world currency markets have swung from optimism to fear and risk aversion which has dragged down sharply the New Zealand dollar cross rate against the yen.
Radio New Zealand's business editor says the NZ dollar has dropped almost four yen, or more than 4%, since 15 January.
Bank of New Zealand strategist Kymberley Martin, says the bank's measure of the global appetite for risk began the year at 67 points, rose to 71, but then plummeted below 50.
Ms Martin says the New Zealand dollar is one of the currencies most affected by risk aversion while the yen is the opposite.
The New Zealand dollar's fall comes despite the likelihood the Reserve Bank will soon raise interest rates while the Bank of Japan is expected to ease monetary policy.
Ms Martin says there are three reasons for the sudden bout of risk aversion: some country-specific developments such as reports of corruption in the Turkish government, weak manufacturing data from China and concerns that, as the United States winds back on printing money, money will flow out of high-yielding emerging markets.
While concerns about individual emerging markets are likely warranted, she says there's little evidence yet of a spill-over into the global financial system.
If that continues to be the case, the current mood of risk aversion is likely to be short-lived and the New Zealand dollar should recover to trade above 86 yen - compared with the low this week below 84 yen - for much of the first half of this year.