Changing the JSE’s operating cycle from the current nine hours (9am-5pm on weekdays) to 24/7 trading would require changes to the local bourse’s operating model to account for the technological resources currently not available after hours, according to JSE CIO Tebalo Tsaoeli.
Business Day in July reported (paywall) that the JSE is monitoring international developments following the London, Nasdaq and New York exchanges announcing a move to 24-hour trading.
Speaking to TechCentral in an interview on Tuesday, Tsaoeli said any such move by the JSE requires careful consideration, including whether the local market has enough liquidity to support a 24-hour trading cycle.
“It really isn’t something that would just happen overnight, and we would have to investigate what the impact would be on the current operating model and our platforms as well,” said Tsoaeli.
“It would entail significant effort with regards to how we configure the platforms. Another thing to consider is the impact on settlement cycles and so forth.”
The JSE runs an on-premises data centre offering co-location services to clients where 70% of R27-billion in daily trading volumes are processed, with intermittent peaks rising as high as R30-billion/day.
The co-location space allows for high-frequency and electronic trading to take place at low latency. As artificial intelligence has become more prominent over the years, the use of AI to facilitate trades has mushroomed. Tsoaeli said the architecture of the JSE’s system allows it to absorb acute peaks in trading volumes without any disruptions.
Cobol to Java
“The current architecture we have adopted was put in place so that we don’t only cater for normal trading volumes, but significant increases in volumes as well,” he said.
Trading algorithms and AI are not the only sources of spikes in trading volumes. Tsoaeli said significant geopolitical events such as the formulation of the GNU following the 2024 general election and the more recent trade wars initiated by US President Donald Trump also led to spikes in the trading of South African shares.
The JSE is also in the midst of modernising some its legacy platforms, including a broker-dealer accounting system that is around 37 years old, as part of efforts to keep trading latencies low.
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Tsoaeli said the system consists of about five million lines of code and runs on an IBM mainframe. Half a million lines of the code have been modernised in Java and now run in the cloud on Amazon Web Services infrastructure.
“In the next 18 months, we will embark on the mass modernisation phase of the initiative where we will focus on transforming the remaining 4.5 million lines of Cobol code so the fully fledged modernised platform can run in the AWS cloud on Java technology,” said Tsoaeli. – © 2025 NewsCentral Media
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