Preparing for Near-24-Hour Trading

Data Readiness, Infrastructure Strategy, & What “Ready” Actually Means

The financial landscape is shifting from traditional market hours toward a near-continuous, weekday trading environment. But as firms talk about “24-hour trading,” the terminology often gets blurred—especially because the terms sound similar, even though they describe different operating realities.

Extended hours typically refer to pre-market and post-market trading around the regular session. Overnight trading spans the gap between when U.S. markets close and when they next open. And “24-hour trading” is often used as shorthand for a 23/5 model: near-continuous weekday trading with a defined operational pause.

Momentum is already building. As overnight participation and trade counts rise across off-hours venues, and U.S. equities are accelerating toward a continuous market. In parallel, SIP Operating Committees have submitted a Plan Amendment to extend SIP hours to near-24-hour dissemination (with a one-hour technical pause each trading day), targeting a December 2026 launch pending SEC review and approval. Exchanges are also pursuing proposals to lengthen trading sessions.

The bigger shift isn’t just “more hours.”

Disruption of the former rhythm of a daily reset has resulted in liquidity forming outside the core session. Leading firms to adopt an “always on strategy, fundamentally changing in risk, liquidity, and system stress. Success in 24/5 trading requires more than just uptime; it requires a holistic strategy encompassing high-fidelity data, resilient infrastructure, and disciplined automation.

Data Readiness: Quality Around the Clock

Near-24-hour trading presents new challenges: managing real-time market data feeds without relying on a predictable overnight reset for batch processing, reconciliation, or maintenance. When the boundaries between trading days blur, maintaining historical integrity becomes harder, not because the data is “worse,” but because fewer natural checkpoints exist to validate it.

This shift disrupts long-standing assumptions around trade date transitions, sequence resets, and reconciliation windows—conditions the industry has historically anchored to a clear open/close cycle. The Securities Industry and Financial Markets Association (SIFMA) has already outlined a reference model for expanded trading hours, including recommendations such as:

• Exchange operating hours occur 23 hours a day, five days a week (e.g., 9:00 p.m. ET Sunday through 8:00 p.m. ET Friday)
• A daily one-hour technical pause (e.g., 8:00–9:00 p.m. ET Monday–Thursday) to support maintenance and operational resets
• A trade date definition aligned to the expanded-hours model (e.g., ending the U.S. trade date at 8:00 p.m. ET)

The key point: if your data processes depend on “the market closing” as a reliable boundary condition, 23/5 forces you to rebuild those controls into the system explicitly.

Why 24-Hour Trading Adds Complexity

Because the same volume of orders is distributed over a longer time period with 24-hour trading, the shift to 24/5 introduces higher volatility, lower liquidity, and wider bid-ask spreads. The removal of the conventional daily pause (allowing systems to reconcile, data to normalize, and liquidity to concentrate) means that firms must always be “on,” leading to:

• A shift in liquidity and spread dynamics outside core hours
• Unlinked or fragmented market risk and price inconsistencies
• The need for sustained-load operations

These new challenges mean financial firms must take a fresh approach to trading, implementing new tools and updated infrastructure to support the evolving landscape. In short, achieving 24/5 readiness requires a normalized data feed that can handle the seamless transition between global liquidity hubs without data fragmentation. For example, Exegy’s Overnight Best Bid and Offer (OBBO) consolidated feed is ideal for the 24/5 discussion because it provides a single, normalized point of access for global data, reducing the complexity of managing disparate feeds across time zones.

Preparing Your Firm for 24-Hour Trading: Defining “Ready”

“Ready” isn’t a binary state—it’s a level of operational excellence. The introduction of 24/5 trading means longer operating cycles with fewer true maintenance windows, so readiness is about sustaining stable operations end to end (market data, trading, risk, operations) over extended hours. More specifically, preparedness can be assessed according to three levels:

Visualize (Level 1) – Can you see overnight activity end-to-end (ingest, normalize, store, query) and reconcile daily breaks/trade dates?

Operate (Level 2) – Operate: Can you deploy changes with no maintenance window (CI/CD discipline, regression testing, rollback) and staff/handoff support?

Respond (Level 3) – Respond: Can you adjust routing/controls/risk parameters when protections are uneven outside core hours (hybrid market behavior)?

Infrastructure Strategy: Building for Resilience

But what does it mean for trading infrastructure to be resilient? In essence, it implies recoverability and operational control over a near-continuous trading week, representing a shift from high availability to continuous availability. Financial firms must intentionally design their infrastructure to avoid planned downtime assumptions, eliminate single points of failure, and minimize human intervention outside of core business hours.

Moreover, those operating globally must position infrastructure to handle shifts in volume as liquidity migrates across time zones. This requires a “follow-the-sun” approach to monitoring and incident response that includes alerting, runbooks, and escalation paths that work outside of daytime hours in the U.S. Because overnight maintenance becomes more difficult with 24-hour trading, resilience demands change management without downtime, complete with disciplined rollout/rollback, configuration control, and regression testing.

Due to global volume shifts, firms must ensure infrastructure can handle dynamic activity patterns as liquidity and message rates span time zones without introducing data gaps or operational instability. As hours expand, tight alignment with venues, clearing/processing timelines, and key technology partners is necessary to maintain a unified operating model.

Due to global volume shifts, firms must ensure infrastructure can handle dynamic activity patterns as liquidity and message rates span time zones without introducing data gaps or operational instability. As hours expand, tight alignment with venues, clearing/processing timelines, and key technology partners is necessary to maintain a unified operating model.

The Role of a Strategic Partner

As institutional players embrace extended trading hours, shifting liquidity patterns, and introducing new overnight price signals, financial firms face increasing pressure to expand their trading windows. To widen the scope of their trading capabilities, they will need to leverage strategic relationships with integrated partners offering market data as a service. This partnership ideally delivers market data access, operational support, and readiness guidance to reduce fragmentation, accelerate preparedness, and simplify ongoing changes as standards evolve.

With our seasoned history of serving the buy side, sell side, and exchanges, Exegy helps firms maintain consistent price discovery when markets expand beyond the core session. The introduction of our OBBO consolidated feed across the after-hours alternative trading systems is just one example of Exegy’s propensity for filling structural gaps using modern trading infrastructure.

What the Future Holds

The pressing need for data readiness to support 24/5 infrastructure goes beyond meeting the demands of the present. With exchange operators expressing more and more interest in near-continuous operations, 24/5 infrastructure is likely a prerequisite for the 24/7 markets of tomorrow. In other words, true 24-hour trading is surely right around the corner, and firms need to be ready.

Leading the Always-On Evolution

Formerly, 24/5 trading was a competitive advantage. Now, it’s the new baseline. The firms that thrive won’t just be the ones that stay awake, but also the ones with the infrastructure to act while others are still processing. As seen with the introduction of Exegy’s OBBO feed, trading rules, tools, and standards change all the time, necessitating a reliable partner to help firms navigate and accommodate these shifts.

Exegy’s market data-as-a-service offering delivers high-quality, low-latency normalized market data so you can gain reliable access to major markets around the globe.

Find out more about Axiom, our fully managed direct feed service.