The US Institute for Supply Management index fell to 48.1, from 48.3 in October. A reading below 50 indicates contraction and economists polled by Reuters had been forecasting a rise to 49.2.
In its final meeting this year, the RBA kept its cash rate at 0.75 per cent after cutting it by 75 basis points this year. Its board agreed to continue monitoring domestic and global developments.
"The board is prepared to ease monetary policy further, if needed, to support sustainable growth in the economy, full employment and the achievement of the inflation target over time," it said.
Tim Kelleher, head of foreign exchange sales at Commonwealth Bank of Australia, said he thought the RBA's statement was neutral and, although the market is ascribing the moves over the past 24 hours to the poor ISM outcome, he isn't buying it.
"All the currencies moved at once. There's been plenty of data that's been good and bad in the last week. I don't think that ISM data is the worst we've seen," Kelleher said.
"Ordinarily, if you saw risk-off in equities, you would see the kiwi come off."
Instead, equity markets have been falling sharply. The broad measure of US shares, the S&P 500 Index, shed 0.9 per cent in its Monday session with markets throughout the Asia-Pacific region following suit.
"I wouldn't be surprised if someone large, like a sovereign wealth fund, had a trade on when volatility was depressed," Kelleher said.
His suspicion is that short positions are being unwound in pre-Christmas positioning.
As for the US-China trade war, the ups and downs of which have been driving global currency trading since last year, Kelleher said he doesn't expect a deal will be signed before the end of the year.
US President Donald Trump is showing no signs of restraint on the trade front, imposing tariffs on steel from Brazil and Argentina, accusing both countries of currency manipulation when both economies are actually in a state of crisis, and threatening worse to come.
The US government has also said it may slap punitive tariffs of up to 100 per cent on US$2.4 billion ($3.6b) of imports of French Champagne, handbags. cheese and other products in retaliation for France's new digital services tax that the US claims will harm its tech companies.
US Trade Representative Robert Lighthizer says the government may also open similar investigations into digital services taxes of Austria, Italy and Turkey.
The New Zealand dollar was trading at 95.10 Australian cents from 95.35 this morning, at 58.74 euro cents from 58.68, at 50.29 British pence from 50.26, at 71.04 yen from 70.85, and at 4.5801 Chinese yuan from 4.5761.
The two-year swap rate climbed to a bid price of 1.1866 per cent from 1.1704 per cent yesterday while 10-year swaps rose to 1.6150 per cent from 1.5400 per cent.
