The Australian Securities Exchange (ASX) has cancelled around A$410 million worth of trades in TPG Telecom shares after a system error mistakenly linked the telco’s ticker to a takeover bid involving a similarly named but entirely unrelated company.

The confusion began when the ASX processed an announcement from private equity firm TPG Capital regarding its $651 million acquisition of software company Infomedia.

Due to an apparent mismatch in the company codes, the release was incorrectly associated with TPG Telecom, triggering automated selling and a sharp drop in its share price.

Within minutes, TPG Telecom shares fell by nearly 5%. More than A$400 million was wiped from the company’s market value before a trading halt was issued.

The ASX later confirmed the trades were made in error and would be reversed in full. However it delivered an apology many saw as insufficiently remorseful, with an ASX spokesperson saying, “This morning our markets announcements office made an error in processing an announcement from Infomedia… TPG Telecom, was incorrectly cross-referenced on that announcement. ASX moved quickly to address the issue when it became clear there was potential for confusion in the market. Shares in TPG Telecom traded for approximately 15 minutes after the market opened before trading was paused.”

Automated selling makes ASX mistakes costly

The incident has added to growing scrutiny of the ASX’s operational resilience.

The exchange operator has faced repeated criticism from investors, regulators and the federal government over a string of failures. Such as a botched A$250 million blockchain clearing system replacement and a 2024 settlement error that triggered a regulatory investigation.

Treasurer Jim Chalmers noted the ongoing issues in a statement backing increased competition in the local market. He welcomed progress on Cboe’s proposal to establish a rival clearing and settlement system.

ASIC is expected to review the circumstances of the latest incident. No formal investigation has been announced, but market sources say the watchdog is monitoring the situation closely.

The ASX has committed to lifting its game and investing in a program of technology upgrades. However, a growing number of critics argue progress has been unacceptably slow.

Soul Pattinson has a 12.6% stake in TPG Telecom. Its chairman Robert Millner, told the AFR, “There has been a continuing saga within the ASX. These things shouldn’t happen, particularly with the technology we’ve got. Strewth.”