The local bourse has snapped its four-day winning streak, retreating from the previous day's all-time high amid geopolitical jitters after Ukraine fired American-made ballistic missiles into Russia for the first time.
The benchmark S&P/ASX200 index on Wednesday finished down 47.7 points, or 0.57 per cent, to 8,326.3, while the broader All Ordinaries dropped 50.1 points, or 0.58 per cent, to 8,579.1.
Overnight Russian President President Vladimir Putin formally lowered the threshold for Russia's use of nuclear weapons after Ukraine fired US-made ATACMS missiles into its territory, apparently striking an ammunition supply depot near the city of Karachev in the Bryansk region.
The US State Department condemned the Kremlin move as "bellicose and irresponsible."
Capital.com analyst Kyle Rodda said another big issue for markets was AI chipmaker Nvidia's third-quarter earnings report, which could be one of the biggest events to close out the year when it's released early on Thursday, Australia time.
Nvidia is now the world's second biggest company and Mr Rodda said it had grown so huge it was becoming a barometer of US economic activity, with its guidance a read on chip demand and investment in AI by tech giant hyperscalers.
Nine of the ASX's 11 sectors finished lower on Wednesday, with health care and utilities slightly higher.
Tech was the biggest loser with a 1.5 per cent dip, after being the biggest gainer on Tuesday.
Xero dropped 1.7 per cent, Dicker Data fell 1.9 per cent and Appen retreated 13.5 per cent.
The big four banks all finished lower, with CBA up 0.5 per cent to $156.38, Westpac down 1.1 per cent to $33.03, NAB dipping 0.6 per cent to $39.32 and ANZ subtracting 0.5 per cent to $32.18.
In the heavyweight mining sector, BHP fell 0.6 per cent to $40.08, Fortescue was flat at $17.75 and Rio Tinto advanced 0.2 per cent to $115.90.
Goldminers gained as the geopolitiical tensions pushed the safe haven metal to a nine-day high of $2,635 an ounce, with Northern Star and Evolution both climbing 1.0 per cent, Westgold adding 0.8 per cent and Genesis Minerals advancing 2.1 per cent.
In the consumer discretionary sector, PWR Holdings plunged 24.6 per cent to a two-year low of $6.85 after the high-tech cooling parts supplier for the performance automotive industry said it expected to earn perhaps as little as $3.2 million in profit this half-year, down from $9.8 million a year ago.
Managing director Kees Weel reiterated this was a transition year for the Queensland company as it moved to a new headquarters in Stapylton.
Nick Scali dropped 1.7 per cent to $13.84 after the furniture retailer said one of its freight forwarders and customs agents had entered liquidation, leading to a significant number of its containers being delayed at ports.
In currency, the Australian dollar was at an eight-day high against its US counterpart, buying 65.23 US cents, from 65.08 US cents at Tuesday's ASX close.
In cryptocurrency, bitcoin was changing hands for $US92,600, or $A142,000 on Australian exchanges, after overnight hitting an all-time high of just under $US94,000.
ON THE ASX:
* The benchmark S&P/ASX200 index finished Wednesday down 47.7 points, or 0.57 per cent, at 8,326.3
* The broader All Ordinaries dropped 50.1 points, or 0.58 per cent, to 8,579.1
CURRENCY SNAPSHOT:
One Australian dollar buys:
* 65.23 US cents, from 65.08 US cents at Tuesday's ASX close
* 101.21 Japanese yen, from 100.53 Japanese yen
* 61.61 euro cents, from 61.49 euro cents
* 51.42 British pence, from 51.37 pence
* 110.49 NZ cents, from 110.53 NZ cents.
