The Australian dollar has fallen more than half a US cent on profit-taking following last week's rally.
At 1700 AEST on Monday, the local currency it was trading at 105.24 US cents, down from 105.85 cents on Friday.
It was trading at 82.42 Japanese yen, up from 82.15 yen on Friday, and at 80.21 euro cents, down from 81.11 euro cents.
The local currency rallied last week, hitting a six-month high at 106.25 US cents in the early hours of the weekend (Australian time) on offshore markets.
This was in the wake of the US Federal Reserve's announcement on Friday that it would spend $US40 billion ($A38.04 billion) a month on bond purchases to stimulate the economy.
It was the third time in recent years the US Fed has attempted to stimulate growth through a policy known as quantitative easing.
ForexCT head of research Stephen Dooley said the Australian dollar had fallen back from its six-month high as traders took profits from the rally.
"I think it is mainly traders booking profits as more of a short-term thing," he said.
Mr Dooley said he expected the local currency to resume its rally in the coming days but that it would meet resistance around the 106.50 US cent level.
"There is going to be very steep resistance around that level, but I think we will smash through it this week."
Mr Dooley said the Fed's stimulus measures were likely to push the US dollar lower over the coming months, which would push its Australian counterpart higher.
"There is one-way traffic for the US dollar, and that is lower."
Meanwhile, Australian bond futures prices fell on Monday.
Commonwealth Bank head of debt research Adam Donaldson said bond prices had weakened in the wake of the Fed's announcement and a crucial German court ruling on the euro zone bailout last week.
"There's been a major move higher in yields in the past week, and that continued today," Mr Donaldson said.
"Clearly the decision in Europe by the German Constitutional Court and then the Fed's decision to announce further QE (quantitative easing) has provided greater support for riskier markets."
At 1630 AEST on Monday, the December 10-year bond futures contract was trading at 96.665 (implying a yield of 3.335 per cent), down from 96.825 (3.175 per cent) on Friday.
The December three-year bond futures contract was at 97.270 (2.730 per cent), down from 97.390 (2.610 per cent).
Keep reading - next article