The full impact of the New Zealand dollar's decline over the past few weeks will take time to work its way into the economy because of the currency hedging policies that many exporters and importers employ, say currency experts.

The kiwi traded at close to five-year lows yesterday at around US68.5c - down US3.4c or 4.7 per cent since June 11, when the Reserve Bank surprised the market with a 25 basis point rate cut.

The currency has been on a roller-coaster ride since the 2009 global financial crisis, when it sank to US49.95c.

It went on to hit a post-float high of US88.43c in 2011 and came close to reaching a new high last July when it traded at US88.38c.


Sharply lower dairy prices have helped drive the kiwi lower this year, but the Reserve Bank's decision on June 11 to cut its official cash rate to 3.25 per cent has sped up its decline.

Exporters and importers typically use currency hedging to lock the currency in at a certain level for a certain time to coincide with export receipts being repatriated or for when import bills need to be paid.

The magnitude of the most recent decline will mean that some exporters are hedged, or locked in, at above the current spot rate, meaning some will be out of the money.

"Typically the Kiwi dollar has settled back at around US75c on any dips, so given that we have moved down from US88c to US75c and now to US68.5c, there will certainly be exporters who have excess cover on," said Tim Kelleher, head of foreign exchange at ASB Bank.

"Having said that, I don't think that you can compare it to the likes of the GFC, when the currency absolutely collapsed," he said.

"Exporters have learned from the GFC in that they don't tend to cover as much as they did previously."

Some businesses covered their exposure on an ad hoc basis, and the bigger the organisation the more stringent the hedging policy tended to be, he said.

Kelleher said it was common for bigger businesses to hedge about 70 per cent of their exposure, and chance their luck with the spot rate for the remaining 30 per cent.


"For importers, they have had five years of luck when the currency has been quite high, so if anyone has been caught out through the lack of cover it has been them, because the pullback has been quite severe," Kelleher said.

Sam Tuck, senior foreign exchange strategist at ANZ Bank, said exporters would be welcoming the decline in the currency but due to hedging policies it could take time to feed through.

"It just means that the full impact, both negative and positive, of the currency's decline will take a while to have an impact on the economy," he said.