The Australian stock exchange has reopened today (20 September) after a database malfunction forced financial officials to suspend trading twice in a single day in what has been described as one of the worst technical glitches faced by the exchange in five years.

In a disastrous Monday for the ninth largest financial exchange in the world, trading was initially delayed at the Australian Securities Exchange (ASX) at opening time for roughly an hour. The problems persisted throughout the day and eventually cut short afternoon trading for 90 minutes.

The normal opening times for the ASX are between 10am and 4pm local time, however, based on an ongoing series of social media updates doors did not open until roughly 11.10am. At the time, the delays were blamed on an "issue with a component that allows ASX to manage individual stocks".

Despite initial claims the problems had been resolved, updates from the exchange quickly proved otherwise – leaving eager traders frustrated throughout the day. After the floor shut early, ASX shares dwindled by 1.4%. According to Bloomberg, they fell a further 0.2 as of 10.25am on 20 September.

In a statement posted to its website, ASX chief executive Dominic Stevens was forced to apologise for the glitches and blamed the chaos on a hardware failure. He was quick to note that the issues were in no way related to hackers or problems with cybersecurity.

"The primary issue arose from a hardware failure in the main database used by the system. This had a number of knock-on consequences that affected the operation of the market," he said. "These included a delay to the market open and the decision to close the market early due to ongoing issues that impacted the proper functioning of the trading platform."

The technical issues were reportedly found in an equities trading system called ASX Trade, Stevens said, adding: "What happened today does not meet the high standards of operations and system reliability that we set ourselves, and that our customers should rightly expect of us. We apologise for the disruption. The issues were not in any way related to cybersecurity."

Top officials at the ASX said they are currently probing the incident and will report back to customers and traders in the near future with further details, Stevens said. Speaking to Reuters after the markets regained functionality, IG Markets chief market strategist Chris Weston said there was "an air of relief".

"Many will be pleased that the technical glitch happened on a day where corporate news flow was limited and the leads from Wall Street were as flat as you will ever see," he said.

"That subdued volatility, however, may change this week with the Bank of Japan and US Federal Reserve meeting dictating that the exchange simply needs to be open, which I am sure it will as these issues happen, but as long as we know it won't happen again then confidence is not materially lost."

As noted, this is not the first technical problem to hit the ASX. In 2011, the stock exchange was forced to freeze trading for four hours just a few minutes after the market opened. Reports from the time show how a few thousands deals went through before the fault stopped all other transactions.

However, in recent years many stock exchanges have been hit with problems. On 14 July, the Singapore Stock Exchange halted trading after the discovery of a flaw in which duplicate trade confirmations were generated. It a separate instance from July last year, the New York Stock Exchange (NYSE) went offline after a "major technical issue".