The firm's head of international economics, Joseph Capurso, says that the aussie could fall to 0.6850 against the dollar - weighed down by RBA policy, the US election and a stalling global economy in the near-term.
Adding that such a drop would put the pair comfortably below fair value, and it would only be a temporary decline before resuming a move higher.
The firm does not expect the RBA to cut rates at its 6 October policy meeting, but if the central bank does deliver then the aussie has more room to fall.
The US election is another key risk to watch as the firm says the pair could fall by 4% over the course of one month if Trump wins the election and by 2-3% if Biden wins and the Democrats take over the Senate.
On the flip side, they argue that the pair could rally by 2-3% if Biden wins but Republicans maintain control of the Senate instead.
In the bigger picture, they make mention that the impact of the election will fade and that should lead the dollar lower with AUD/USD forecast to range between 0.71 and 0.82 but more centered around 0.77.
The firm maintains its house view that AUD/USD will reach 0.78 before the end of 2021.