Nasdaq’s Push for a 23-Hour Trading Day Marks a Break With Tradition

Nasdaq has formally asked U.S. regulators to approve a nearly round-the-clock trading schedule, proposing a 23-hour, five-day market that would dramatically extend how and when investors trade American equities. The plan represents one of the most ambitious structural changes ever sought by a major U.S. exchange, positioning Nasdaq to compete more directly with crypto markets, overseas equity venues, and retail brokerages that have steadily pushed the boundaries of after-hours trading. Traders immediately began assessing the implications through the benchmark Nasdaq 100 (Zorrox: NQ100.), which stands to become the most visible testing ground for the liquidity and volatility dynamics of an almost continuous market.

A Bid to Capture Trading That Has Already Moved Elsewhere

The motivation behind Nasdaq’s request is not complicated: investors are already trading around the clock—but not on regulated U.S. equity exchanges. Retail platforms offer extended hours. Crypto markets run nonstop. Asian and European exchanges provide liquidity windows that overlap U.S. nights and early mornings. In practical terms, the trading day has expanded; the infrastructure simply has not.

Nasdaq’s proposal attempts to reclaim that activity by offering an official venue where price discovery can occur under the exchange’s supervision rather than in fragmented, lightly regulated alternative systems. The exchange argues that investors—particularly retail traders—should not be forced into opaque or thinly supervised markets when major events occur outside traditional hours. Corporate earnings, geopolitical shocks, monetary policy developments, and macro data often break at times that leave U.S. equities partially paralyzed. A 23-hour schedule, according to Nasdaq, brings structure to activity that already exists in a scattered form.

The proposal also acknowledges a hard truth: equity markets have become less U.S.-centric in their temporal structure. Nasdaq is positioning itself to reclaim leadership before someone else fills the gap.

How a Near-Continuous Market Could Reshape Trading Behavior

A 23-hour session does not merely extend the clock—it changes the rhythm of market participation. Liquidity at the edges of existing after-hours trading is notoriously uneven. Spreads widen. Price movements amplify. High-frequency firms adjust their models to account for lower turnover. If Nasdaq secures approval, it will be responsible for creating an orderly market across periods when liquidity has historically evaporated.

That challenge carries opportunity. The exchange could attract new market makers exclusively dedicated to overnight trading. It could capture order flow currently routed to dark pools or cross-border brokers. And it could create a more globally integrated pricing cycle, allowing U.S. equities to respond to international news in real time rather than in a single violent gap at the cash open.

For investors, the expansion may also erode the psychological significance of the opening bell itself. If news is absorbed continuously rather than in bursts, intraday volatility patterns could shift. Some expect smoother transitions. Others anticipate more persistent waves of algorithmic trading, especially during thin overnight sessions.

The reality is that no one fully knows how a 23-hour equity market behaves in practice. But Nasdaq is betting that the market structure will adapt as it always has: liquidity flows to where opportunity exists.

Regulatory Approval Is Far From Guaranteed

The SEC is unlikely to rubber-stamp such a fundamental change. Regulators will evaluate whether a nearly continuous market increases systemic risk, invites manipulation, or strains firms required to supervise compliance around the clock. Exchanges, brokers, clearing firms, and market makers would need to adjust operations significantly. That means staffing changes, new surveillance architecture, expanded risk controls, and revised capital models.

The Commission will also scrutinize retail exposure. Extended-hours trading already carries elevated risk for less-experienced investors. A near-continuous session amplifies those risks unless guardrails are enhanced. Nasdaq will be expected to demonstrate how it intends to maintain orderly markets during off-peak periods when liquidity may be meaningfully lower.

Still, the regulatory climate is not inherently hostile to experimentation. The SEC has overseen major structural reforms over the last decade, including approval of competing market models, alternative trading systems, and periodic call auction proposals. Nasdaq’s 23-hour plan is more ambitious, but it lands in a landscape where structural innovation is no longer taboo.

Why Nasdaq Is Making This Move Now

The timing is not accidental. Retail engagement remains elevated. Algorithmic and quantitative strategies have become more adaptable to nontraditional trading windows. And global capital flows increasingly react to news cycles that do not respect U.S. trading hours.

Nasdaq is also facing competitive pressure from exchanges that have embraced innovation, from crypto venues offering perpetual access to new tokenized equity projects that aim to blur asset-class boundaries entirely. Allowing U.S. equities to remain confined to a limited schedule risks ceding relevance to markets willing to trade continuously.

For Nasdaq, the proposal is strategic defense as much as market modernization. The exchange cannot allow competitors to define what “open market” means in the next decade.

What a New Market Structure Would Mean for Investors

If approved, the move would reshape how traders interact with news, liquidity, and risk. Traditional “after-hours earnings spikes” may become milder as reaction windows expand. Overnight hedging behavior would change. Some investors might welcome the flexibility, while others could be forced to refine risk management practices that previously relied on market closures as natural circuit breakers.

Institutional trading desks will likely adjust in stages, modeling liquidity patterns before committing major flows. Retail participation may skew heavily toward early adoption, especially among those accustomed to extended-hours platforms. Meanwhile, global investors may find it easier to trade U.S. equities during their home-market hours, increasing international order flow.

In essence, a 23-hour trading day would make the U.S. equity market behave more like a global commodity market—responsive, continuous, and far less anchored to the symbolism of the opening and closing bell.

Tips for Traders

• Track sentiment around Nasdaq 100 (Zorrox: NQ100.) as investors price in potential shifts to liquidity, volatility, and overnight risk once extended trading becomes institutionalized.

• Prepare for new volatility patterns; traditional open-close dynamics may fade as markets digest news continuously instead of in discrete bursts.

• Review risk models that assume overnight gaps; a near-continuous session will alter how portfolios respond to macro or geopolitical shocks.

• Monitor SEC commentary closely, as regulatory conditions attached to approval could materially influence how viable the expanded schedule becomes for active traders.