The World Federation of Exchanges (WFE) has published new research concluding that extended trading hours, including near round-the-clock markets, are technologically feasible, but their long-term sustainability depends on coordinated reform across clearing, settlement and payment infrastructure.
In Extending Exchange Trading Hours, the WFE examines proposals from major U.S. exchanges to expand equity trading toward 22- or 23-hour daily sessions, placing them within a broader global landscape of more than 60 exchanges with varied session designs. While extended access may improve participation for retail and international investors, the report warns that liquidity timing, funding availability and settlement alignment must evolve in parallel if market quality is to be preserved.“While around-the-clock trading may enhance market accessibility and flexibility, its effective implementation and sustainability depend on deep coordination across trading, clearing, settlement, and regulatory systems,” says WFE CEO Nandini Sukumar.
Extended access, not yet 24/7
The research makes clear that true 24/7 equity trading remains rare. What is emerging – particularly in U.S. markets – are extended 22- or 23-hour sessions across five days, rather than continuous seven-day trading.
NYSE Arca, Nasdaq and Cboe Global Markets have all signalled interest in longer trading windows, working with regulators and industry bodies to explore operational alignment. However, the report stresses that a move to full 24/7 trading would require far more significant changes across market infrastructure.
“The real impact of 24/7 trading is architectural,” observes Olivier Masdebrieu, Chief Technology Officer at Horizon Trading Solutions. “For decades, trading systems were built around end-of-day boundaries that acted as safety checkpoints. In a continuous model, those checkpoints disappear. Every system, from order gateways to risk engines, must now operate with no assumption that the day ever ends. That requires a complete rethink of how data, memory, and system state are managed.”
For technology providers and exchange operators, this creates a structural distinction: matching engines and order management platforms can generally operate on a near-continuous basis, but the surrounding ecosystem remains bounded by traditional operating cycles.
Settlement windows remain the constraint
A central theme of the report is the risk of asynchronous operating windows across central counterparties (CCPs), central securities depositories (CSDs) and real-time gross settlement (RTGS) systems.
Extended trading can push execution activity beyond the hours in which clearing, funding and payment systems are fully operational. Without corresponding changes to these systems, settlement mismatches and liquidity timing risks may increase, particularly over weekends and holidays.
The paper’s case study of foreign exchange settlement illustrates the point. Analysis of Continuous Linked Settlement (CLS) cycles shows how late-evening equity trades in an extended U.S. session could fall outside CLS cut-off windows, potentially requiring prefunding or alternative FX arrangements for cross-border investors. While not an insurmountable obstacle, such timing misalignments introduce additional liquidity and capital efficiency considerations.
The broader implication is that execution capability alone does not determine whether extended trading will function smoothly. Clearinghouses, custodians and payment system operators must be aligned if the model is to scale without unintended friction.
Liquidity may not follow the clock
Beyond infrastructure, the report examines whether longer trading hours automatically translate into deeper liquidity. Evidence from 24/7 cryptocurrency markets suggests otherwise.
Although crypto trading is continuous, volumes and volatility remain concentrated around traditional business hours in major financial centres. Weekend activity is materially lower, and off-peak periods can exhibit thinner liquidity and greater susceptibility to volatility. Continuous access, in other words, does not guarantee evenly distributed participation. If similar patterns emerge in extended equity markets, thinner overnight sessions could place greater emphasis on risk controls, surveillance and adaptive market-making strategies.
“Extending trading windows sounds attractive, but liquidity is not evenly distributed around the clock,” notes Mark Montgomery, Chief Commercial Officer at xyt. “If markets fragment into thinner overnight sessions, participants could face higher costs and less reliable price formation unless the supporting infrastructure evolves at the same pace. Price formation is the real test. When the primary market is not fully functioning, spreads widen, liquidity thins out and quotes become more one sided. That is the risk with pushing trading into quieter hours.”
Incremental change over wholesale redesign
The WFE argues that extending trading hours within a five-day framework may represent a pragmatic intermediate step, allowing exchanges and market participants to test operational resilience and liquidity dynamics before contemplating fully continuous markets.
Such sequencing provides time for regulators and infrastructure providers to address questions around reference pricing, corporate actions processing and settlement cut-offs, areas historically structured around discrete trading days.
Taken together, the WFE’s findings suggest that extended trading hours represent less a simple expansion of access and more a market structure coordination exercise.
Execution systems are largely capable of running longer. The decisive question is whether clearing, settlement, funding and liquidity provision frameworks can adapt in parallel. Without that alignment, extended sessions risk fragmenting liquidity or introducing settlement frictions into an ecosystem still designed around defined business hours.
As exchanges push toward longer trading days, the debate is shifting from technological feasibility to systemic readiness, and from session design to infrastructure synchronisation.
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