The benchmark S&P/ASX200 index on Wednesday finished up 1.2 points, or 0.01 per cent, at 8,142.1, while the broader All Ordinaries climbed 3.1 points, or 0.04 per cent, at 8,364.3.
The Federal Reserve has made it clear it will announce an interest rate cut during Thursday's pre-dawn hours, Australia time.
But it's unknown whether the cut will be a standard quarter of a percentage point, or a "jumbo" cut of half a percentage point.
Capital.com analyst Kyle Rodda said the market's reaction would depend not just on the size of the cut, but whether Fed chairman Jerome Powell pushed back on the idea US interest rates would decrease by a full percentage point by year-end.
Two other central banks are scheduled to announce rate-cut decisions before Australia's Reserve Bank holds its meeting on Tuesday.
"Every man, woman, and their dog still awaits the Bank of Japan's interest rate decisions, the Bank of England, and the Fed's ahead of the RBA's call next week," Moomoo market strategist Jessica Amir said.
Domestically, traders are also watching for Australian employment figures, which will be released on Thursday and could influence trader sentiment, said Ashley Glover, CMC Markets's head of sales trading for Asia Pacific.
"We are due for a blockbuster back end of the trading week," Mr Glover said.
Five of the ASX's 11 sectors finished higher on Wednesday and five closed lower, with consumer staples unchanged.
Utilities were the biggest mover, rising 1.3 per cent as Origin Energy climbed 2.2 per cent.
The big four banks were mixed, with NAB up 1.4 per cent to $39.42, CBA adding 0.2 per cent to $143.32 and Westpac climbing 0.4 per cent to $33.16, while ANZ dipped 0.2 per cent to $31.15.
In the heavyweight mining sector, BHP and Rio Tinto both slipped 0.9 per cent, to $39.19 and $109.74, while Fortescue added 0.3 per cent to $17.43.
Chalice Mining climbed 14.6 per cent to $1.455, a day after its Gonneville platinum group element-nickel-copper-cobalt project 70km northeast of Perth was granted major project status by the Western Australia government.
In health care, Imugene grew 6.3 per cent to 5.1c after its potential treatment for a rare form of bile tract cancer received orphan drug status from the US Food and Drug Administration.
The Australian dollar had climbed further against its weakening US counterpart, buying 67.66 US cents, from 67.59 US cents at Tuesday's ASX close.
ON THE ASX:
* The benchmark S&P/ASX200 index finished Wednesday up 1.2 points, or 0.01 per cent, at 8,142.1
* The All Ordinaries gained 3.1 points, or 0.04 per cent, at 8,364.3
CURRENCY SNAPSHOT:
One Australian dollar buys:
* 67.66 US cents, from 67.59 US cents at Tuesday's ASX close
* 95.78 Japanese yen, from 95.07 Japanese yen
* 60.85 euro cents, from 60.76 euro cents
* 51.37 British pence, from 51.18 pence
* 109.08 NZ cents, from 109.10 NZ cents
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