At noon AEST on Wednesday, the benchmark S&P/ASX200 had fallen 7.9 points, or 0.1 per cent, to 7,770.2, while the broader All Ordinaries was down 6.1 points, or 0.08 per cent, to 8,009.7.
The cash rate remained at 4.35 per cent for the fifth consecutive meeting, which was widely expected by economists and traders.
While the RBA's move was initially overlooked and caused "barely a ripple" in equities or currency, Capital market analyst Kyle Rodda said the decision appeared more on the hawkish side.
The board's statement reiterated that anything is "on or off the table" to get inflation back to target, with RBA governor Michele Bullock telling reporters after the decision that the board had debated a rate hike but not a rate cut.
""We need a lot to go our way if we're going to bring inflation back down," Ms Bullock said at the media conference.
At midday, six of the ASX's 11 sectors were lower, two were flat and three were higher.
The energy sector was the biggest gainer, rising 0.6 per cent, with uranium miners faring well after the coalition government unveiled its nuclear policy. Deep Yellow rose 2.3 per cent, Boss Energy climbed 1.5 per cent and Paladin was close behind with a 0.9 per cent increase.
The policy proposes homes could be powered by nuclear energy by 2035, and promised to build seven nuclear power plants at existing coal-fired plants.
Coalminers saw their shares slip following the announcement on Wednesday, with Yancoal sinking 1.2 per cent and Whitehaven down 0.6 per cent.
Meanwhile, the four big banks had stumbled at midday, as ANZ dropped 0.4 per cent, NAB fell 0.3 per cent and CBA and Westpac both dipped by 0.2 per cent.
Helia Group had slid 16.6 per cent to a six-month low of $3.52 over uncertainty whether its contract to provide lenders mortgage insurance to Commonwealth Bank would be renewed when it expires at the end of 2025.
CBA intends to solicit new bids for the contract, Helia indicated, with Helia CEO Pauline Bright-Johnston issuing a statement saying the company welcomed the opportunity to extend its relationship with Australia's biggest bank.
One Australian dollar was buying 66.55 US cents, up from 66.13 US cents at Tuesday's ASX close.