By Martina Rejsjo
Equity market structure is entering a new phase — one where the closing bell no longer signals the end of the day. Once limited to specialized venues, 24-hour trading is quickly entering the mainstream, driven by rising demand from market participants and subsequent adoption by a growing contingent of industry leaders.
Despite the momentum, key questions remain unresolved. While markets like FX and crypto can provide a basic blueprint for what 24-hour trading as an industry standard might look like, the highly regulated equities market brings unique considerations that require thoughtful adaptation across the entire trade lifecycle. Forward-looking firms should already be assessing how their infrastructure, processes and strategies must evolve to stay competitive.
Trade surveillance teams, in particular, have reason to pay attention. Overnight trading won’t just stretch the clock; it fundamentally alters market dynamics. Off-hours often bring reduced liquidity and heightened volatility, creating new risks and behaviors to monitor. Regulatory uncertainty adds another layer of complexity, with existing frameworks not always clearly aligned with 24/5 activity. The result is a new risk profile — one that can’t be addressed by simply extending daytime procedures into the night.
New Hours, New Risks
Surveilling a 24/5 market isn’t just a matter of working longer hours. It requires new thresholds, new procedures, new staffing models and more.
This is due to the fact that manipulative trading behaviors change and tend to be more prevalent in a thinly traded market. Fewer participants and shallower books mean even modest trades can move prices significantly. That makes it easier — and cheaper — to engage in abusive trading practices like spoofing, pump-and-dump schemes or outright price setting, and firms must ensure they are vigilant in protecting themselves and their clients from this potential behavior.
These risks are compounded by the lack of regulatory clarity around how 24/5 equity markets will actually function. Several critical questions remain unanswered:
- How will Reg NMS apply after hours?
- Is the SIP going to operate 24/5? If not, how will protected quotes be handled?
- How will best execution obligations be defined and enforced?
Even infrastructure-based protections such as limit up/limit down bands and market-wide circuit breakers may be unavailable, since they’re tied to SIP data that may not be active at night. While this clarity should emerge as conversations on overnight trading continue to mature, the uncertainty today reflects the challenge of extending a highly regulated market structure into a time window it was never originally designed to accommodate.
Bottom line: extending existing trading protocols isn’t enough. Market participants must ensure their trade surveillance programs offer the flexibility to adapt to both shifting market dynamics and a shifting regulatory environment.
An Operational Playbook for 24/5
While crypto surveillance might not be a 1:1 comparison, it still offers several lessons that can be applied to 24-hour equity trading. Many of the operational challenges associated with overnight trading — from position reconciliation to continuous monitoring — have already been addressed by firms in that space. There are useful lessons here, particularly around surveillance automation, staffing and real-time risk assessment.
One clear takeaway is the need for adaptable surveillance systems — platforms that can easily duplicate procedures and apply different thresholds based on time of day. Automation can play a key role here, enabling firms to dynamically recalibrate logic and sensitivity levels as conditions shift. As 24-hour equities trading gets off the ground, there will be a natural period of iteration: firms will need to tune parameters, observe how they perform and adjust accordingly. That means flexibility isn’t just a nice-to-have; it’s essential to getting the framework right.
Firms trading equities around the clock can also look to crypto markets for cues on how to staff surveillance. Off-hours trading introduces more than just lower liquidity. It often features less experienced traders and fewer counterparties available to absorb errors or unexpected volatility. Automation can handle a lot, but especially in these early stages, human oversight remains essential. Firms need the ability to take proper action in real time, not retroactively. For global organizations, a “follow-the-sun” model with experienced compliance professionals is the most straightforward path to achieving true 24/5 coverage.
As market structures evolve, there’s an opportunity to take the best of both worlds — combining the regulatory discipline of traditional equities with the operational resilience of crypto. That hybrid mindset will be critical as 24/5 trading becomes more widespread.
This is where Eventus comes in. Our longstanding presence in crypto means we’ve supported 24/7 trading environments for years, and we understand the operational complexity that comes with it. Our Validus platform is designed to run continuously and make it easy to adjust surveillance parameters on the fly. Our procedures are flexible, scalable and quick to adapt — whether you’re expanding into new time zones, asset classes or market structures.
Just as important, we bring deep regulatory expertise to every client engagement. We understand how to evolve surveillance programs in line with changing expectations — not just technically, but strategically. In moments of market transition, that guidance is crucial.
While there is still much uncertainty, particularly from a regulatory perspective, surveillance teams shouldn’t wait. The firms that begin preparing now will be better positioned as the conversation matures so they can focus on the strategic benefits of 24-hour trading, not just the operational challenges.
At Eventus, we’re helping our clients prepare for what’s next — whatever hours the market keeps. If you’re exploring 24/5 trading, we’d love to talk about how we can support your surveillance journey.
