In the history of finance, innovation has often been driven by necessity rather than choice. From the creation of stock exchanges to the rise of electronic trading and the proliferation of digital platforms, markets have evolved in step with investor demands, technology and globalisation. As the world’s economy becomes increasingly interconnected, another transformation is on the horizon: extended trading hours – or more accurately, the transition to a world where markets never truly close, writes Marc Biro, managing principal at Capco.
The idea of stretching beyond the confines of the traditional closing bell is not new. However, a convergence of forces – technological capacity, investor expectation, global competition, and the relentless march of digital assets – is now making this evolution not just desirable, but inevitable. Marketplaces must remain relevant in a world where information and opportunity move at the speed of light.
The charge is being led by US exchanges and regulators, with the New York Stock Exchange Group announcing plans last autumn to extend weekday trading to 22 hours a day on the NYSE Arca exchange, and other US exchanges also extending open times. Interest in extending trading hours is now spreading to the London Stock Exchange and to exchanges in Asia.
A market already in motion
Recent data highlights just how quickly extended trading hours are becoming embedded in the fabric of US equity markets through the mechanism of off-hours sessions. According to NYSE research, Q2 2025 set new records with over two billion shares and $62 billion traded in off-hours sessions – accounting for 11.5% of all US equity trading during the quarter.
Pre-market activity in particular has accelerated, with more than 3.74 billion shares changing hands on June 12 alone, a single-day record. The pre-market in Q2 2025 represents nearly 7.1% of total daily volume, up from just 3.0% in 2023, while post-market participation has slowed to 4.9% in Q2 2025 from highs of 5.5% in 2024. Retail investors are playing an outsized role in this shift: during NYSE’s Arca pre-market session, nearly 8 out of 10 trades in non-S&P 500 stocks are retail-driven versus 4 out of 10 for S&P 500 stocks.
Overnight trading in 2025 YTD is small – around 0.11% of total shares and 0.15% of notional, with an April peak near 0.14%/0.17% – versus roughly 11% during extended hours; and because sub-$ prints make up about 13.5% of core-hours volume but only 2.7% overnight (ranging 1.5 – 5.4% by month), stripping those trades out further lowers any headline estimate of the overnight share.
A notable feature of off-hours trading patterns is the effect of earnings days, when volumes surge. Off-hours activity can rise by around 6X in S&P 500 stocks, and by around 3x in Russell 2000 stocks, reflecting the market’s demand for immediacy around corporate disclosures.
Together, these numbers paint a picture of both momentum and imbalance. Extended trading is no longer peripheral – it is becoming a significant share of daily liquidity. At the same time, much of the growth is concentrated in specific moments (earnings days) and segments (retail-driven small- and mid-cap names). This suggests that extending trading hours further is not just about capacity, but also about creating a market design that can scale equitably.
Breaking free from legacy constraints
Historically, stock exchanges have mirrored the industrial workday. A rigid schedule – 9:30 to 4:00, give or take – was designed to fit with the daily rhythms of clerks as they filled out key paperwork and made the necessary phone calls. That structure served its purpose when transactions required physical presence, and the settlement of trades was a manual process.
Today, that world is gone and news does not wait for the opening bell. A corporate earnings report, a geopolitical development, or a technological breakthrough can occur at any hour. In our interconnected global economy, such events ripple instantly across continents. Yet investors, bound by outdated market hours, find themselves forced to wait – sometimes overnight, sometimes longer – before acting on critical information. That gap distorts price discovery, creates volatility spikes and undermines investor confidence.
Extended trading hours addresses this fundamental mismatch. By keeping markets open for longer windows – and ultimately on a continuous basis – exchanges can allow investors to respond in real time. This not only creates fairer markets but also brings greater inclusivity, giving retail investors and global institutions alike access to opportunities whenever they arise.
Beyond investors: The operational challenge
The transition, however, will not be simple, particularly in terms of the operational impact. Trading around the clock places unprecedented demands on market infrastructure, risk management systems, surveillance capabilities and regulatory oversight.
Firms will need to ensure that trading platforms can withstand higher throughput, that cybersecurity defenses remain constantly vigilant, and that compliance controls do not suffer lapses during extended cycles. Market surveillance will no longer operate within the limited market hours, instead becoming a globalised, continuous discipline requiring both human expertise and advanced machine-learning tools.
The human factor cannot be ignored. Staff across trading, risk, compliance and operations will need to adapt to new models of work. That may mean leveraging automation and global talent pools to provide seamless coverage or designing rotational shifts that protect employee well-being while preserving institutional resilience. Extended hours will test not just technology but also organisational culture and leadership.
The imperative of harmonisation across divisions
For large financial institutions, another layer of complexity lies in firm-wide harmonisation. Their investment banking, asset management and wealth management arms often operate in silos, each with distinct client bases, product suites and operational processes. Extended trading hours threaten to exacerbate these silos unless firms adopt a unified strategy.
Consider a scenario where an institutional client can execute after-hours trades in certain products through one division but is blocked from parallel opportunities in another. Or where liquidity management is optimised in the investment bank but fragmented in the asset management arm. Such inconsistencies not only erode client trust but also increase cost and risk.
True success in extended hours will require coordination: harmonised order-routing protocols, shared liquidity pools, consistent client service standards, and integrated technology platforms that span across divisions. Firms that achieve this alignment will create seamless experiences, protect operational efficiency, and reinforce their competitive edge. Those that fail may find themselves undermined from within, competing against their own inconsistencies.
The digital asset wake-up call
If there are any doubts about the urgency of this transformation, one need only look at the digital asset markets. Tokenized equities, digital bonds, cryptocurrencies and other blockchain-based products already trade 24/7. For a growing generation of investors, this is the norm. Their portfolios span both traditional securities and digital tokens, and they expect constant access, instant settlement and global liquidity.
The result is competitive pressure. Every hour that traditional exchanges remain closed, investors are reminded that digital-first alternatives can provide what legacy systems cannot. This is not a theoretical risk; it is a shift that is already reshaping investor behavior and capital flows.
Integrating digital assets into broader trading infrastructure and governance will be necessary not only to serve clients but also to maintain systemic competitiveness. Extended trading hours in traditional markets are, in many ways, a defensive response to the disruption posed by digital assets.
Toward a resilient, global marketplace
Extended trading hours lay the groundwork for a truly global market. Removing time barriers lets capital flow seamlessly across regions, deepens liquidity, and helps markets absorb shocks, react to geopolitical events, and reflect real-time macro shifts for steadier price discovery.
They’ll also spur innovation – but demand real operational change. Exchanges will build tools and analytics for continuous markets, while risk, liquidity and settlement frameworks evolve. Firms must align teams and invest in technology and risk management. The bigger risk is inaction: 24/7 digital-asset markets have already reset expectations, and traditional markets must catch up.