After-Hours Trading: Market Data, Adoption, and What Comes Next 

After-hours trading is no longer just an “extra session.” As markets move toward 24/5, it changes what firms need from their technology stack, especially around market data visibility, onboarding speed, and operational readiness. 

To explore what’s shifting, Exegy sat down with Jason Wallach, CEO of Bruce Markets, to talk about the changing market data requirements for after-hours trading and the technology decisions that make broader adoption possible. From how data is packaged and distributed to how participants build confidence outside core hours, the conversation points to a simple reality: when liquidity is thinner, market data matters more. 

What is After-Hours Trading? 

Before we get into the rest of this conversation, it’s worth getting on the same page about what counts as after-hours trading. 

After-hours trading (sometimes called extended-hours trading) means trading that happens outside the regular U.S. equities session of 9:30 a.m. to 4:00 p.m. ET.  

That can include pre-market, post-market, and increasingly overnight sessions. And for this piece, we’ll focus mostly on the overnight portion of after-hours trading because Bruce ATS operates from 8:00 p.m. to 4:00 a.m. ET, from Sunday night through Friday morning, which lines up more naturally with a wider range of global investor time zones than the traditional U.S. day.  

After-hours trading gives market participants more flexibility to react to news and trade outside the core session, but the market can behave differently outside those hours. Liquidity can be thinner, and spreads can be wider, which is exactly why market data visibility and transparency matter so much more once you step outside the normal trading day. 

Why is After-Hours Trading Growing?  

If you zoom out, after-hours trading is growing for a pretty simple reason: what used to feel optional now comes with real expectations. 

Bruce Markets echoed that sentiment. When asked why it was the right moment to launch Bruce ATS for overnight trading, here’s how Wallach responded: 

The simplest reason is that we believed overnight equities represented a tremendous opportunity, but one that was unrealized due to a lack of mature infrastructure. We felt there was a gap to be filled. The overnight outage in August 2024 was a prime example: when a market relies too heavily on a single venue or a single thread of infrastructure, stress events can quickly turn into cancellations, confusion and gaps in coordination. 

Today, what once felt like a lightly used extension of the day is now a global, customer-facing session with real expectations around continuity, transparency and trust. With demand and expectations for overnight trading reaching new heights, we believe the ecosystem needs healthy competition and redundancy so brokers can deliver a more stable experience instead of concentrating risk in one place.” 

That point about infrastructure maturity isn’t theoretical. The 2024 overnight disruption was a real stress test, showing how quickly concentrated participation can spiral into cancellations, confusion, and coordination gaps when volumes spike. It also made something clear: APAC-driven demand wasn’t a niche edge case. The scale surprised the market and accelerated a shift from overnight as an add-on to overnight as a session that needs real resilience and redundancy. 

Why Does Market Data Matter More After-Hours? 

After-hours trading can look and feel different from the core session. Liquidity is often thinner, spreads can be wider, and price moves can be sharper, so the signal traders rely on during the day matters even more once you step outside regular hours.  

Wallach echoed that in our conversation. When we asked what signals matter most and how firms can see those signals in a way that supports real decision-making, here’s how he responded: 

Firms still evaluating whether or not to jump in need to face a fundamental reality: the overnight market is the first place stocks trade on Sunday night. It’s the only way to participate in the market’s first shot at price discovery following the weekend. 

In terms of specific signals, firms tend to care about whether liquidity is consistently actionable, whether the markets behave predictably, and whether overnight spreads and volatility are understandable enough to support a defensible client experience. As volumes grow – and they are, with approximately 130 million shares traded a night in January – liquidity quality will continue to get better. It only makes sense to get involved now. 

We also believe that those signals only matter if they show up where traders and brokers already look. Broad, familiar market data distribution is crucial. We distribute Level 1, Level 2, and Last Sale data in partnership with Nasdaq Data Services and via more than ten market data redistributors globally. That means quotes and prints can be consumed via standard workflows, without requiring new plumbing.” 

That last line is the bridge to adoption: the more after-hours market data shows up in standard workflows, the easier it is for firms to incorporate overnight sessions into their existing operations—without treating it like a one-off exception. Nasdaq has described this same goal in its data partnership with Bruce Markets: making Bruce ATS data accessible through existing Nasdaq connections overnight. 

What Slows Adoption in After-Hours Trading? 

Even with growing demand, after-hours adoption doesn’t stall because people don’t want it. It stalls because overnight markets still get treated like a side project—and because a few persistent assumptions can create real blind spots once you’re trying to support clients through the session. 

The Mindset Gap 

When we asked Bruce Markets what people still get wrong about overnight markets, here’s how they responded: 

One persistent assumption is that overnight is still in an experimental stage. That’s not the case. Many of the world’s leading brokers are highly active, and there are now multiple venues serving them. In fact, the tightest markets are often found on the newer entrants’ platforms. The competitive landscape is being redefined in real time. 

Related to this: many firms are under the misconception that a single overnight feed can represent the entire market. But overnight visibility is venue-specific. An ATS can be technically up while still creating blind spots through venue-specific thresholds (including voluntary halts in active symbols), while those same names may continue trading elsewhere.” 

The Visibility Problem 

That venue-specific visibility point matters. In after-hours sessions, you don’t automatically get the same comfort that firms are used to during the core trading day. If you’re watching a single source, you can think you’re seeing the market—when you’re just seeing one venue’s view of it. 

The Operational Reality 

Then there’s the practical side: even when firms want to participate, supporting overnight sessions means integrating new workflows while also taking on new exception risk. Wallach described it like this: 

Operationally, firms slow down when new integration work and new exception risk are introduced at the same time. Corporate actions are a good example: when information arrives late, or trading begins before the full picture is disseminated, the downstream risk climbs quickly.

We try to reduce that friction in a few concrete ways. The common theme: simplicity by design.  

First, Bruce ATS is set up for seamless market access. The matching engine is hosted in the Equinix NY4 data center, which is also home to the trading engines and routers of a significant population of brokers, liquidity providers, and other market centers. For those not co-located in NY4, Bruce ATS supports FIX 4.2-based order entry through several financial extranets. 

Second, our overnight session is orderly by design: limit orders, price/time priority, ±20% price bands from a defined reference price and automatic cancel at session end to create a clean operational handoff to the next day. For certain features, such as the price bands, we opted to harmonize with our competitors rather than introduce unnecessary complexity by competing on something that would not deliver increased value to investors. 

Third, Bruce Markets systematically suspends trading in symbols around pending corporate actions to reduce operational friction for participants. Our process is designed to be comprehensive and effective, delivering confidence to clients as they evaluate risk and optimize operations. 

Finally, the venue is backed by leading institutions – built on Nasdaq technology and leveraging experienced operational capabilities through our strategic investors. We can’t solve for all the operational hurdles, but we can make it as easy as possible for brokers to say yes.” 

The Takeaway 

That’s the adoption story in a nutshell: after-hours trading scales when the market is observable, the operational risk is manageable, and firms can connect without reinventing their stack. 

What Comes Next for After-Hours Trading? 

At this point, the demand story is clear. The bigger question is whether the plumbing around after-hours (and especially overnight) can scale fast enough to meet it—and do it without turning every busy night into an operational fire drill. 

It’s not just trading hours. It’s the ecosystem. 

When we asked Wallach what needs to happen for institutional participation to grow meaningfully over the next 12–18 months, he didn’t point to one silver bullet. He pointed to a few basics that must work together: 

The demand for overnight trading is there. The question is whether the infrastructure can catch up. Firms need comprehensive market data, orderly post-trade processes and timely corporate-action dissemination to reduce operational risk. These features need to be present across the entire ecosystem. Anything less is a recipe for chaos. Things are heading in the right direction overall – they’re simply not moving fast enough. Firms that purport to connect the world to the markets and foster transparency need to get moving, because this space is only going to get more crowded.” 

Conclusion 

After-hours trading is no longer a side session. It’s where global demand is showing up first, and where the market is getting an early look at what 24/5 really requires. In our conversation with Bruce Markets, one theme kept coming up: adoption doesn’t hinge on interest—it hinges on infrastructure. Firms need market data that’s comprehensive and visible inside existing workflows, plus the operational guardrails that make overnight participation feel manageable rather than risky. And as more venues enter the space, the bar is rising quickly. The next phase of after-hours trading won’t be defined by who extends the clock the furthest—it’ll be defined by who helps the ecosystem scale with transparency, resilience, and stability. 

Exegy offers connectivity to Bruce via Axiom’s data-as-a-service model. Contact a sales representative to get started.  

About Bruce Markets  

Bruce Markets LLC (“Bruce”) is a registered broker-dealer and member of FINRA and SIPC. Bruce operates an Alternative Trading System (ATS) which provides liquidity and execution services in NMS stocks during the hours of 8:00 p.m. to 4:00 a.m. ET. FINRA BrokerCheck reports for Bruce are available at:https://brokercheck.finra.org For more information on the Bruce ATS, visit the SEC Form ATS-N filings website link.  Trading outside of regular U.S. trading hours involves the following risks: lower liquidity, higher volatility, changing prices, unlinked markets, news announcements, and wider spreads.  Full disclosures are available at: https://www.brucemarkets.com/disclosures/.