The Australian Securities Exchange (ASX) was forced to pause trading on Monday morning due to unspecified market data issues.
The technology problems began at about 10.17am and ruled out trading for the remainder of the day.
The exchange upgraded the issues to having a “critical operations impact” and set the trading session to an “enquire” state.
The Enquire session state “locks the market so no trading messages/orders may be entered, amended or cancelled”, according to technical documentation.
It is “used while an investigation into the cause and implications of the issue is undertaken”.
“The ASX equity market is currently paused and there is no trading while we investigate market data issues,” the exchange said in a brief statement on its website.
“ASX apologises for the disruption and is working to rectify the issue as soon as possible.”
The exchange said at 3pm that the issues would keep trading systems offline for the remainder of Monday, with a view to opening again on Tuesday.
It said the root cause had been identified but did not disclose it in status updates.