The New Zealand dollar fell over half a cent from late trading Friday, following a large transaction early this morning.
ANZ senior foreign exchange strategist Sam Tuck said the market was still expecting US interest rates to rise sooner than later, despite a fairly neutral speech by the head of the US Federal reserve, Janet Yellen, over the weekend.
"Later that morning we saw a sudden drop of about half a cent in the New Zealand dollar," he added.
"Lots of rumour and innuendo flying about what caused that move but no confirmed evidence of anything untoward. At the moment, it's just being put down to a large flow, a large sell order."
A short time ago, the kiwi was trading at 83.48 US cents, at 89.60 Australian cents, 50.39 British pence, 0.6322 euro, 87.00 yen and 5.14 renminbi.
Sharemarket climbs following 'interesting' day
The sharemarket was higher today with the benchmark Top 50 Index gaining 16 points to 5183.
Forsyth Barr investment advisor Damian Kearns said it was an interesting day on the market, with a number of companies reporting results.
"Metlifecare has announced the first of their earnings, by 37 percent, which is at the top end of their guidance. Also of note, Heartland New Zealand meets their guidance, with a rebound in full-year profit."
Shares in Metlifecare rose 15 cents to $4.50.
Xero rose $1.25 to $25.
Inturie rose 6 cents to $2.96.
Heartland shares fell 1 cent to 94 cents and Chorus shares ended unchanged at $1.73.