S&P Global Ratings lowered the Australian Securities Exchange (ASX) issuer credit rating to 'A+/A-1' from 'AA-/A-1+'. The outlook remains stable.

An Australian Securities and Investments Commission (ASIC) report prompted the downgrade. The report identified shortcomings in governance, risk management, and a culture prioritizing short-term financial performance over infrastructure resilience.

Ongoing deficiencies caused several operational failures. These failures include the cancellation of the CHESS replacement project.

S&P expects ASX revenue to remain strong. Addressing identified issues requires significant investment over several years.

S&P warned of a further downgrade if risk controls and practices fail to improve within two years.