"The Aussie dollar remains the big winner in G10," says Francesco Pesole, FX Strategist at ING Bank. "CME reporting a large surge of call option volume driven by aggressive speculative flows ahead of the RBA announcement."

Demand for AUD is etched into a GBP/AUD daily chart that shows a clear downward-sloping channel for the exchange rate. Sure, the pair has recently consolidated around 1.8860, but it's hard to look at such an image and be anything but bearish:

Turning to RBA day, what will matter for currency markets is how the central bank frames its hike. Does it confirm that it stands ready to act again, or does it signal that it thinks it has done enough to get ahead of the inflationary risks?

The former, and we get a stronger AUD, the latter, and it cools on the day, allowing GBP/AUD to become more entrenched around that 1.8860 consolidation zone.

Currency tacticians are split on what might happen.

"A dovish hike could still present some headwinds to AUD, due to market positioning and pricing, so we raise the conviction level on short AUD/NZD to 3/5 to 2/5 to reflect this," says Dominic Bunning, an analyst at Nomura.

Strategists at UBS take the other side of the bet, saying RBA policy sees it reiterate their "Attractive view on the AUD."

"Even if the RBA does not hike next week, it would likely be seen as a 'hawkish hold,' and any setbacks in the AUD are likely to be short-lived, in our view," they say in a recent note.

David Forrester, a strategist with Crédit Agricole, says the market is currently 70% priced for a hike, meaning "the knee-jerk reaction in the AUD to a hike would be higher."

From here, investors will look at the details, including the vote breakdown; "we would not be surprised to see a split vote," says Forrester.

"We could then see a sell-the-fact correction given aggressive positioning and the RBA striking a cautious tone on further tightening, given high uncertainty," says ING's Pesole.

Money market pricing shows traders are priced for three more 25bp rate hikes by the RBA this year, which is quite punchy and means there is some scope for disappointment on the day.

"While a spilt vote would weigh on the currency, we think the RBA’s rhetoric will be hawkish with an eye on containing inflation expectations supporting the AUD," says Forrester.