The S&P/ASX200 rose 4.4 points, or 0.05 per cent, to 8,546.4 , as the broader All Ordinaries gained 4.9 points, or 0.06 per cent, to 8,775.1.
In early trading the top 200 pushed ahead of its record close of 8,555.8 on Valentine's Day, but had slipped by lunchtime.
The index has not yet pipped its intraday record level of 8,615.2, also set on February 14.
Local markets shrugged off a mixed Wall Street session overnight, as weak US jobs and manufacturing data indicated Trump administration trade policy was weighing on an already slowing US economy, Capital.com market analyst Kyle Rodda said.
"Although investor sentiment remains robust, largely because of confidence - misplaced or otherwise - about progress in US trade negotiations and strong tech results, the spectre of a slowdown in growth continues to feed niggling fears that the equity market has gotten too far ahead of itself," he said.
On Wednesday, Commonwealth Bank became the first ASX-listed company to be valued at $300 billion as its share price cracked $182 for the first time.
Despite the global headwinds and frothy local valuations investors were still buying, market strategist at trading platform Moomoo Jessica Amir said.
"While the Australian and US economies are growing weaker than expected (Australia hardly at all), both share markets will probably soon smash through their record all-time highs," she said.
"What's encouraging investors to enter the local market is that only 60 per cent of Australia's biggest stocks are pulling it higher."
Ms Amir said the S&P/ASX200 could reach as high as 8,800 points if a bullish expansion continued.
By midday, five of 11 local sectors were trading higher.
Financials were down after CBA's record run on Wednesday, both the sector and Australia's biggest company fell 0.1 per cent.
Materials, technology, real estate, telecommunications and consumer staples stocks were lifting the bourse.
Large cap miners were mixed, but Fortescue jumped 1.1 per cent as BHP and Rio Tinto traded modestly either side of break-even.
Gold is trading relatively flat since yesterday, consolidating around $US3,400 ($A5,230) an ounce and holding local miners and explorers back.
The ongoing rare-earths stoush between China and the US sent critical minerals miners higher, helping Pilbara Minerals rise 4.2 per cent and rocketing Lynas Rare Earths shares up more than nine per cent, making Lynas the top-200's best performer.
Energy stocks are 0.4 per cent weaker after rallying on Wednesday, as oil prices continued to consolidate at their lowest levels since 2021.
Brent crude futures are trading at $US64.66 a barrel, easing slightly as Saudi Arabia flagged July price cuts for crude buyers in Asia and after the US reported an uptick in diesel and petroleum inventories.
Information technology was the best performing local sector, up 0.5 per cent and tracking Wall Street's tech heavy Nasdaq - the only US index to finish higher overnight.
The Australian dollar is buying 64.98 US cents, up from 64.63 US cents on Wednesday afternoon, after weaker US economic data weighed on the greenback.