ASX Regulatory Challenges and CHESS Platform Transformation: A 2025 In‑Depth Analysis

The Australian Securities Exchange (ASX) entered 2025 under increased regulatory scrutiny as concerns surrounding operational resilience, governance and the long-running CHESS replacement project became increasingly important to Australia's financial-market infrastructure.

The ASX regulatory challenges and CHESS platform transformation in 2025 were closely connected. CHESS—the Clearing House Electronic Subregister System—is central to the clearing, settlement and ownership infrastructure supporting Australia's equities market. Its replacement therefore represents one of the most significant technology and operational projects undertaken by the ASX.

During 2025, the Reserve Bank of Australia (RBA) and Australian Securities and Investments Commission (ASIC) took additional regulatory action following a significant CHESS settlement incident in December 2024. The regulators also monitored another capacity-related CHESS issue during the April 2025 period of heightened market volatility.

At the same time, ASX continued progressing its replacement program, with Release 1 focused on clearing services and Release 2 intended to replace settlement and subregister functions.

For investors, the developments matter because ASX operates critical financial-market infrastructure. Operational resilience, regulatory compliance and successful technology transformation can therefore have implications extending beyond ASX itself.

What Is CHESS?

CHESS stands for the Clearing House Electronic Subregister System.

It supports important post-trade functions for Australian securities markets, including the clearing and settlement of trades and maintenance of electronic ownership records.

The system is therefore different from the ASX trading platform that investors interact with when buying or selling shares.

Trading determines transactions between market participants. Clearing and settlement are the subsequent processes through which obligations are managed and securities and funds are transferred.

CHESS has been operating for decades, making its reliability increasingly important as market volumes, technology requirements and cybersecurity expectations have evolved.

The ASX has been working on replacing the existing platform with a new technology architecture delivered in stages.

Why Is the ASX Replacing CHESS?

The existing CHESS platform is an ageing system that has become increasingly difficult to maintain and modify.

The replacement project was originally conceived as a distributed-ledger technology project, but the current replacement program uses a different technology approach following the project's reset.

The new program is being delivered through two major releases:

Release 1: Clearing

Release 1 focuses on replacing the clearing component of CHESS.

The RBA's September 2025 assessment said Release 1 was scheduled to go live in April 2026.

Release 2: Settlement and Subregister

Release 2 is intended to replace the settlement and subregister functions.

The RBA stated in September 2025 that Release 2 was expected to go live in 2029, with elements of the program still in planning.

This staged approach is significant because the clearing and settlement functions are both critical, but they also have different technical and operational requirements.

Regulatory Concerns Intensified in 2025

One of the most important developments occurred on 31 March 2025, when the RBA and ASIC announced additional action concerning ASX's operational risk management.

The regulators said they had deep concerns about the potential for operational incidents to affect CHESS's ability to reliably service the Australian equities market until the replacement system was implemented.

The RBA took the unusual step of reassessing the compliance of ASX Clear and ASX Settlement outside its normal annual assessment cycle.

It downgraded their compliance assessment against the Operational Risk standard from "partly observed" to "not observed." The RBA uses the latter rating when serious issues require immediate action.

ASIC also directed ASX to engage an approved expert to conduct a technical review of CHESS.

The actions demonstrated that regulators were treating CHESS resilience as an immediate operational issue rather than simply a long-term technology project.

The December 2024 CHESS Settlement Failure

The regulatory developments in 2025 were partly driven by an incident that occurred on 20 December 2024.

According to the RBA's subsequent assessment, the incident resulted from a virtual-memory capacity limit affecting the number of settlement participants that could be processed in a CHESS settlement batch.

The issue was triggered when a settlement participant resigned and ASX removed that participant from CHESS.

A calculation error involving outdated logic caused the available memory allocation for settlement participants to be substantially reduced.

The incident meant ASX Settlement did not complete settlement obligations by the value date.

The RBA said the incident also exposed deficiencies involving:

• Incident response
• Governance
• Resourcing
• Contingency arrangements
• Change management
• Operational risk management

These issues became central to the regulatory focus during 2025.

A Second CHESS Capacity Issue Emerged in April 2025

The CHESS challenges did not end with the December incident.

During the April 2025 period of extreme market volatility associated with US tariff announcements, high trading volumes combined with a participant-system change created another potential capacity problem.

The RBA reported that ASX faced a risk that trades executed on 7 April 2025 could fail to settle two days later because of constraints relating to the number of unique Holder Identification Numbers (HINs) in a CHESS settlement batch.

The issue was ultimately managed without the same settlement failure experienced in December.

However, the incident increased regulatory concern because ASX had known about the relevant capacity issue since January 2025.

The RBA said the existence of the problem was only reported to it the day before the potential settlement impact.

This highlighted an important issue for regulators: replacing an ageing system does not remove the need to maintain and manage that system safely until the replacement becomes operational.

The Challenge of Running Old and New Systems at the Same Time

One of the most difficult aspects of the CHESS transformation is that ASX must maintain the existing platform while simultaneously developing and testing its replacement.

The RBA noted that ASX employees supporting the current CHESS system were also involved in activities associated with the replacement project.

This created competing demands for specialist personnel.

The regulator expressed concern that key subject-matter experts were being heavily utilised across business-as-usual operations and the replacement project.

This creates a practical transformation challenge.

ASX cannot simply reduce resources supporting the current system while it remains critical infrastructure. At the same time, insufficient resources for the replacement project could affect delivery.

The transition therefore requires careful management of:

• Engineering resources
• Testing
• Cybersecurity
• Incident response
• Business continuity
• Vendor management
• Regulatory reporting
• Industry coordination

CHESS Replacement Testing in 2025

Testing became a major focus during 2025.

ASX opened its Industry Test Environment for Release 1, allowing market participants to begin testing the replacement clearing services.

The ASX's stakeholder communications show that the Industry Test Environment activities commenced in February 2025.

However, the RBA's September assessment noted that testing had experienced delays because of a higher-than-expected number of code defects.

The regulator said these defects could delay Release 1 if they were not remediated.

This illustrates why the transition cannot be judged simply by whether a target launch date exists.

Successful implementation also requires:

• Comprehensive industry testing
• Defect resolution
• Operational readiness
• Participant readiness
• Cutover planning
• Rollback arrangements
• Business continuity
• Regulatory assurance

The Importance of Cutover and Rollback Planning

A financial-market infrastructure system cannot be treated like an ordinary software upgrade.

If an ordinary business application experiences downtime, operations may be temporarily interrupted.

A problem with clearing or settlement infrastructure can have wider consequences because numerous market participants depend on the system.

The RBA therefore said it would closely monitor ASX's planning for the transition, including cutover and rollback strategies as Release 1 approached.

A robust rollback strategy is particularly important because it provides a mechanism for responding if unexpected problems arise during implementation.

Government Response to the CHESS Inquiry

The regulatory environment surrounding CHESS also changed during 2025.

The Australian Government published its response to the statutory inquiry into competition in clearing and settlement and the CHESS replacement project on 3 March 2025.

The inquiry made 12 recommendations.

The Government response recorded:

• 2 recommendations actioned
• 1 supported
• 3 supported in principle
• 6 noted

The response was tabled on 27 February 2025.

The inquiry was important because the CHESS replacement project is connected not only to technology but also to competition, market structure and the regulatory framework governing clearing and settlement infrastructure.

Competition in Clearing and Settlement

CHESS operates within a broader financial-market infrastructure ecosystem.

Regulators have also been considering how competition can operate within clearing and settlement services.

ASIC announced new clearing and settlement rules in February 2025 as part of reforms intended to promote competition. The changes formed part of the broader regulatory response to Australia's financial-market infrastructure environment.

For ASX, this means the CHESS transformation is taking place alongside changes to the regulatory framework in which clearing and settlement services operate.

Operational Resilience Became a Central Issue

The events of 2025 reinforced the importance of operational resilience.

Operational resilience refers to an organisation's ability to continue providing critical services despite technology failures, cyber incidents, system disruptions or other unexpected events.

For a market infrastructure operator, resilience involves more than preventing incidents.

It also requires the ability to:

1. Detect problems quickly
2. Escalate incidents appropriately
3. Communicate with stakeholders
4. Activate contingency arrangements
5. Restore services
6. Complete settlement obligations
7. Learn from incidents

The RBA said the December incident exposed deficiencies in ASX's incident response capabilities, governance and accountability.

Cybersecurity Is Another Major Challenge

The CHESS transformation also occurs against a backdrop of increasing cyber risk.

Financial-market infrastructure represents critical national infrastructure, making cybersecurity a major consideration.

During the 2024–25 assessment period, the RBA and ASIC identified a need for ASX to improve its cyber strategy and workplan.

ASX subsequently developed a more comprehensive cyber-resilience roadmap and began preliminary work on industry-wide cyber-resilience testing.

These initiatives are important because a modernised settlement system needs to address both traditional technology failures and cyber threats.

Governance and Risk Culture

Technology transformation also exposes organisational governance issues.

The RBA's 2025 assessment continued to identify concerns around ASX's risk culture, governance and controls.

The regulator said ASX continued to underperform other major financial institutions across its risk-culture metrics, with particular gaps involving risk capabilities and risk governance and controls.

This is relevant because major technology projects often fail for reasons extending beyond software.

Effective governance requires:

• Clear accountability
• Appropriate escalation
• Independent assurance
• Transparent reporting
• Adequate resources
• Effective risk identification
• Timely remediation

The Financial Importance of CHESS

CHESS is not merely an internal ASX technology system.

It supports a core part of Australia's financial-market infrastructure.

A reliable clearing and settlement system allows trades to move from execution to final settlement.

If settlement is disrupted, participants may face:

• Liquidity pressures
• Operational disruption
• Reconciliation problems
• Increased counterparty risk
• Additional administrative costs

The RBA noted that the December 2024 failure created liquidity pressures for some participants that were relying on the CHESS batch settlement process.

This explains why regulators place such importance on the resilience of the platform.

What CHESS Transformation Could Mean for ASX

A successful CHESS replacement could provide several potential benefits.

Modern Technology Infrastructure

A replacement system can reduce dependence on ageing technology and make future system development more manageable.

Greater Scalability

Modern infrastructure can potentially provide greater capacity to accommodate increasing transaction volumes.

Improved Resilience

A redesigned architecture can incorporate improved redundancy, monitoring and contingency arrangements.

Better Operational Flexibility

A modern platform may make it easier to implement future enhancements and adapt to changing market requirements.

Stronger Market Infrastructure

The replacement program ultimately aims to provide a more sustainable foundation for Australia's clearing and settlement infrastructure.

However, these benefits depend on successful implementation and long-term operational performance.

Key Risks Investors Should Monitor

Investors following ASX should monitor several factors during the transformation.

Release 1 Delivery

The first major milestone is the clearing replacement.

Testing, defects, participant readiness and cutover arrangements are important indicators.

Release 2 Complexity

Release 2 involves settlement and subregister functionality and is therefore a particularly important stage of the transformation.

Current CHESS Resilience

The existing platform must remain reliable until the replacement is complete.

Regulatory Actions

ASIC and the RBA continue to supervise ASX closely.

Project Costs

Large technology programs can require substantial investment.

Resource Constraints

Specialist employees may be required simultaneously for legacy-system support and transformation activities.

Cybersecurity

New infrastructure creates opportunities to improve resilience but also introduces new technology and integration risks that must be managed.

What the 2025 Developments Mean for ASX Investors

For investors researching ASX Limited, CHESS should be considered within the company's broader operational and regulatory profile.

The key issue is not simply whether a new technology platform launches on schedule.

Investors can monitor:

• Regulatory assessments
• Project milestones
• Industry testing
• Independent assurance
• Technology expenditure
• Operational incidents
• Cybersecurity developments
• Governance changes
• Participant readiness
• Long-term project economics

The CHESS transformation is a multi-year program, meaning individual announcements should be considered within the broader implementation timeline.

Frequently Asked Questions

What is CHESS on the ASX?

CHESS stands for Clearing House Electronic Subregister System. It supports the clearing and settlement of Australian equities and electronic records of securities ownership.

Why is ASX replacing CHESS?

The existing CHESS platform is ageing and increasingly difficult to maintain. ASX is replacing it through a staged program involving clearing first, followed by settlement and subregister functions.

What happened to CHESS in 2025?

During 2025, regulators investigated and responded to operational concerns arising from the December 2024 settlement failure and a further capacity-related issue that emerged during the April 2025 period of high market volatility.

When was CHESS Replacement Release 1 expected to launch?

As of the RBA's September 2025 assessment, Release 1 was scheduled for April 2026. It covers clearing services.

What does CHESS Replacement Release 2 cover?

Release 2 is intended to replace the settlement and subregister functions of the existing CHESS system. The RBA's September 2025 assessment said it was expected to go live in 2029.

Why is CHESS important to investors?

CHESS supports the post-trade infrastructure required to clear and settle Australian equity transactions and maintain electronic ownership records. A reliable system is therefore important to the functioning of Australia's securities market.

Are regulators monitoring the CHESS replacement?

Yes. ASIC and the RBA have maintained close oversight of the project and ASX's operational resilience. In March 2025, ASIC directed ASX to engage an approved expert to conduct a technical review of CHESS.

Conclusion

The ASX regulatory challenges and CHESS platform transformation in 2025 represented two closely connected issues: the immediate need to strengthen the resilience of the existing CHESS system and the longer-term requirement to replace it with modern infrastructure.

The year brought increased regulatory scrutiny following the December 2024 settlement failure, another capacity-related issue during the April 2025 market volatility and continuing concerns around operational risk, governance and resourcing.

At the same time, ASX continued progressing CHESS Replacement. Release 1, focused on clearing, was targeted for April 2026, while Release 2, covering settlement and subregister functionality, was expected in 2029 according to the RBA's September 2025 assessment.

For investors, the transformation is significant because CHESS forms part of Australia's critical financial-market infrastructure. The key areas to follow include project delivery, independent assurance, operational resilience, regulatory assessments, cybersecurity, participant testing and the costs associated with the transition.

The outcome will depend not only on replacing legacy technology but also on ASX's ability to strengthen governance, risk management, contingency planning and operational resilience across the wider organisation.

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