Nasdaq is moving closer to a fundamental change in the way U.S. stocks are traded, confirming plans to expand its equity market to 23 hours a day, five days a week.

The move would create a nearly continuous U.S. stock market, allowing investors around the world to trade Nasdaq-listed securities throughout most of the day and night. Under the planned schedule, trading would run from 9 p.m. to 8 p.m. Eastern Time, with a one-hour pause each day for processing and transition.

Nasdaq expects the new schedule to begin on December 6, 2026, subject to the readiness of the industry's securities-information infrastructure and applicable regulatory requirements.

The change could significantly reshape the U.S. equity market and further blur the traditional distinction between daytime Wall Street trading and the increasingly active overnight market.

Nasdaq currently operates its equity market across pre-market, regular and post-market sessions.

The regular U.S. market remains open from 9:30 a.m. to 4 p.m. Eastern Time. Investors can already trade outside those hours, but liquidity, market participation and available infrastructure are generally more limited.

The new structure would add a dedicated overnight session from 9 p.m. to 4 a.m. ET.

The existing daytime extended session would continue from 4 a.m. through 8 p.m.

That would create 23 hours of trading each weekday, with the only daily interruption occurring between 8 p.m. and 9 p.m. ET.

Trading would begin at 9 p.m. ET Sunday and continue until 8 p.m. Friday, meaning the market would remain closed on weekends.

Nasdaq says investor behavior is changing.

Global investors increasingly want access to U.S. stocks during their own business hours rather than waiting for the New York trading session.

An investor in Asia, for example, may prefer to trade U.S. equities during the local daytime instead of participating during overnight hours.

Nasdaq's regulatory filing says the exchange is responding to rising demand for overnight trading and competition from alternative trading systems that already offer extended access.

The exchange is also responding to the growth of digital assets and tokenized securities, which trade continuously or nearly continuously.

The traditional stock market therefore risks losing some trading activity to platforms that operate on more flexible schedules.

Nasdaq is not creating overnight trading from nothing.

Alternative trading systems and brokerage platforms have already expanded access to U.S. equities during nighttime hours.

Nasdaq's own filing specifically points to platforms including Blue Ocean, Bruce and Interactive Brokers as part of a market structure increasingly capable of supporting overnight trading.

The difference is scale.

Moving overnight trading directly onto a major national securities exchange could increase standardization and liquidity while creating a more unified market-data system.

Nasdaq's move does not eliminate the traditional 9:30 a.m. to 4 p.m. session.

The exchange has said that the main U.S. session will continue to determine official opening and closing prices through Nasdaq's Opening Cross and Closing Cross.

That distinction is important because liquidity tends to be deepest during normal trading hours.

The overnight market will probably have different characteristics.

Trading volumes may be lower, spreads may be wider and individual price movements could be more sensitive to relatively small orders.

One potential benefit is a faster reaction to international news.

Corporate announcements, geopolitical developments, economic data and major events often occur outside normal U.S. market hours.

Under the current system, investors frequently react through futures, pre-market trading or other instruments before the stock market officially opens.

A more continuous Nasdaq could allow investors to trade the affected stocks directly for a larger portion of the day.

That could reduce some of the abrupt price adjustments that occur at the opening bell.

It could also create new risks.

Investors may have less time to digest breaking information before prices adjust, potentially increasing volatility during thin overnight sessions.

The biggest beneficiaries may be investors outside North America.

Nasdaq represents a huge share of global equity-market capitalization, and the exchange has argued that U.S. stocks are increasingly important to investors around the world.

A nearly continuous trading schedule would allow international investors to participate when their own markets are open.

That could increase the global integration of U.S. equities.

It may also encourage more capital to flow into American companies, particularly among retail investors and institutions that currently find U.S. market hours inconvenient.

A major challenge is ensuring that the systems supporting stock trading can operate safely for 23 hours.

Nasdaq has been developing new market-data products specifically for the expanded schedule. The exchange introduced its Nasdaq Plus data products to help customers prepare for the greater volume and information demands associated with 23/5 trading.

The broader industry also needs the Securities Information Processors and related infrastructure to support the new overnight sessions.

That is one reason the December 6 start date remains subject to operational readiness.

The development also highlights a broader competitive pressure.

Cryptocurrency markets operate 24 hours a day, seven days a week.

Nasdaq's move does not make stocks equally continuous, but it narrows the gap.

As tokenized securities and other blockchain-based financial instruments become more sophisticated, traditional exchanges have a greater incentive to offer flexible trading schedules.

The Nasdaq filing explicitly notes competition for order flow from digital-asset and tokenized-security markets.

The transition to 23-hour trading could eventually change how investors think about the U.S. stock market.

The opening bell would become less important for determining when investors can transact, while market participants would increasingly focus on the quality of liquidity available at different times.

Brokers may also need to reconsider how they manage risk, margin requirements and customer support.

For companies, the change could provide access to a broader pool of investors and potentially make U.S. capital markets more attractive globally.

For investors, it creates greater flexibility — but also raises the possibility of more frequent volatility outside traditional U.S. hours.

Nasdaq's move is therefore not simply an extension of the trading day.

It is part of a broader transformation in which financial markets are becoming increasingly global, electronic and continuous.

When the new schedule is expected to begin on December 6, U.S. stocks will still have a one-hour daily pause and remain closed on weekends.

But the traditional concept of Wall Street's nine-to-five trading day will be much closer to disappearing.