Australian shares opened lower on Thursday as the major banks led losses across the index following Commonwealth Bank’s biggest-ever one-day plunge.

The S&P/ASX 200 Index retreated 10.80 points, or 0.1 per cent, to 8619.60 at 10.24am AEST – putting the benchmark at risk of falling for a fifth consecutive session.

Financials were the weakest as Commonwealth Bank dropped 0.7 per cent after falling by 10.4 per cent on Wednesday in its biggest loss on record after a weaker-than-expected quarterly profit and concerns about changes to negative gearing. ANZ lost 0.9 per cent, Westpac by 1.1 per cent and National Australia Bank by 1.6 per cent.

ASX Limited bucked the trend to rise 1.3 per cent after it appointed Euronext executive Anthony Attia as chief executive from September 1, following a global search process caused by the departure of Helen Lofthouse.

Including financials, there were nine sectors weaker. Technology was mixed as WiseTech Global dropped 4.5 per cent and Xero by 1.7 per cent after its profit fell to $NZ167.4 million ($137 million) for the full year ended March 31, down from $NZ227.8 million the year prior.

Megaport rocketed 24.6 per cent after it secured $254 million worth of long-term network and storage contracts through its newly minted Latitude.sh subsidiary and reaffirmed its FY26 guidance. The three contracts across two US-based customers represent $90.6 million in annualised recurring revenue.

BHP spiked to a new intraday record of $62.70 before last trading 1.5 per cent higher following further overnight gains in copper. Materials were further supported by a 0.7 per cent jump in Rio Tinto and a 0.8 per cent rise for Fortescue.

Stocks in focus

In company news, Coles retreated 0.9 per cent as the Federal Court ruled that the supermarket giant had misled shoppers over discounts advertised in its store promotions.

Listed car parts retailer Bapcor tumbled 20.4 per cent after it downgraded its FY26 EBITDA guidance from $150 million to $160 million provided in February to between $144 million and $150 million due to deteriorating trading conditions since the start of the Middle East conflict.

GrainCorp dropped 11.6 per cent after its first-half profit fell to $33 million from $69 million 12 months earlier as oversupply in global grain markets and weak pricing compressed margins across the supply chain.

Worley rose 2.9 per cent after it announced a new $300 million stock buyback, following the end of a $500 million buyback three weeks ago.

OOh!media climbed 1.9 per cent as it said first-quarter revenue growth in Australia accelerated ahead of expectations, but warned pressure on billboard earnings and higher rents on premium sites would weigh on first-half margins.