The benchmark S&P/ASX200 index on Wednesday came less than a point away from eclipsing its July 18 record for its highest close ever, rising 51.8 points, or 0.6 per cent, to finish at 8,756.4.
In late afternoon trading, the ASX200 also moved less than four points away from breaking its intraday record of 8,776.4, also set July 18.
The broader All Ordinaries on Wednesday gained 48.7 points, or 0.54 per cent, to 9,015.4.
The ASX200 began the day in the green but the gains accelerated after the Australian Bureau of Statistics released its June quarter consumer price index readout, which is seen as the most important factor in deciding whether the Reserve Bank will cut rates next month.
That report showed that the RBA's preferred inflation metric, trimmed mean inflation, was 2.7 per cent in the year to June 30, in line with expectations but down from 2.9 per cent in the year to March 31.
Headline inflation came in at 2.1 per cent, slightly under expectations of 2.2 per cent.
Betashares chief economist David Bassanese, one of just a few economists who correctly predicted that the RBA wouldn't cut rates this month said that an August rate cut was now a "done deal".
He predicted further cuts in November and February.
Economists with ANZ, J.P.Morgan, Commonwealth Bank, NAB and AMP all reiterated that they expected a rate cut in August, with NAB's Tapas Strickland saying it was locked in.
Six of the ASX's 11 sectors finished higher and five closed lower on Wednesday.
The consumer staples sector was the biggest mover, rising 1.3 per cent as Coles gained 1.7 per cent and Woolworths added 1.6 per cent.
In the heavyweight financial sector, all of the big four banks gained ground.
ANZ rose 1.3 per cent to $30.70, NAB added 0.7 per cent to $38.47 and CBA and Westpac both grew 1.6 per cent, to $176.99 and $33.72, respectively.
In the mining sector, West African Resources advanced 3.9 per cent to $2.39 after reporting its Kiaka goldmine in Burkina Faso was ramping up to full commercial operations after pouring its first gold on June 26.
IGO dropped 7.2 per cent to $4.64 after the nickel, copper and cobalt miner announced disappointing fourth-quarter production results at its Greenbushes lithium mine in WA.
Mineral Resources added 2.3 per cent to $30.78 after posting what RBC Capital Markets analyst Kaan Peker called a "strong operational finish to FY25," while Pilbara rose 3.0 per cent to $1.725 after the lithium miner announced that production was up four per cent in the June quarter.
Elsewhere in the sector, BHP dipped 0.5 per cent to $40.22, Fortescue rose 0.6 per cent to $18.19 and Rio Tinto lost 1.0 per cent to $115.81.
After the market closed Rio Tinto announced it made $US4.5 billion ($6.9 billion) in profit after tax in the six months to June 30, down 22 per cent from a year ago.
The company said it was a "very resilient" set of financials given the price of iron ore had fallen 13 per cent and its WA operations was impacted by Tropical Cyclone Zelia in the first quarter.
The Australian dollar was buying 65.12 US cents, from 65.25 US cents at 5pm on Tuesday.
ON THE ASX:
* The benchmark S&P/ASX200 index on Wednesday gained 51.8 points, or 0.6 per cent, to 8,756.4
* The broader All Ordinaries added 48.7 points, or 0.54 per cent, to 9,015.4
CURRENCY SNAPSHOT:
One Australian dollar buys:
* 65.12 US cents, from 65.25 US cents on Tuesday.
* 96.36 Japanese yen, from 96.69 Japanese yen
* 56.37 euro cents, from 56.35 euro cents
* 48.76 British pence, from 48.88 British pence
* 109.20 NZ cents, from 109.32 NZ cents
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