The end of the trading hours for US stocks: Nasdaq moves towards an uninterrupted financial system

Once, Asian investors trading US stocks had to stay up late to monitor the markets. Now, this dilemma is about to change—but at a much more complex cost than imagined. In mid-December 2025, Nasdaq officially submitted an application to the U.S. Securities and Exchange Commission (SEC), proposing to extend US stock trading hours from the current five days a week, 16 hours a day (pre-market/market hours/post-market) to five days a week, 23 hours a day. Once approved, US stocks will trade from 21:00 on Sunday until 20:00 on Friday, leaving only a one-hour maintenance window (20:00-21:00) each day. The logic behind this is far beyond the surface reason of “meeting Asian investors’ needs”—it is a highly coordinated systemic engineering effort aimed at pushing traditional finance toward a “never-closing” tokenized future.

From Evening Trading to 24/7: When Will US Stocks Adopt New Rules?

The question of when US stocks start trading might seem simple, but this reform involves a comprehensive upgrade of the entire traditional financial system. Besides Nasdaq itself, multiple stakeholders are involved, including broker-dealers, clearing agencies (like DTCC), regulators, and listed companies. To support a 23-hour trading system, all market participants must undergo deep transformation:

Brokerage and dealer costs will skyrocket. Around-the-clock trading means customer service, risk control, and trading maintenance systems must operate 24/7, leading to a sharp increase in shift staffing costs and system maintenance expenses. This is not just a technical upgrade but a major adjustment in human resource allocation.

Clearing agencies face system reconstruction. DTCC and its subsidiary, DTC, need to upgrade their trading coverage and clearing systems to extend service hours until 4 a.m., aligning with the “next-day settlement for night trading” rule. This involves redesigning transaction data flows, margin management, and risk monitoring across the entire chain.

Corporate disclosure rhythms are disrupted. Financial reports and major announcements will no longer be priced only during trading hours but may react immediately at non-traditional times, greatly increasing investor relations management complexity.

This also explains why Nasdaq is not rolling out 24/7 trading all at once but leaving a one-hour window—according to Nasdaq disclosures, this hour is mainly for system maintenance, testing, and trade settlement. Under the current centralized clearing and settlement system, a physical downtime period is necessary for batch data processing, margin settlement, and guarantee calculations. This is the Achilles’ heel of traditional finance architecture.

For Asian traders in the GMT+8 zone, the 5×23 model indeed offers tangible benefits—no need to stay up late to participate in US stock trading in real-time. But behind this progress, Nasdaq is essentially conducting a stress test to examine the capacity of existing financial infrastructure under continuous operation. In contrast, blockchain-based crypto assets inherently support 7×24×365 trading, relying on decentralized ledgers and smart contracts to achieve atomic settlement without downtime or key process bottlenecks.

Liquidity Fragmentation Risks: Rebuilding Price Power Under 5×23

While extending trading hours theoretically attracts more cross-time-zone capital, in reality, it presents a complex double-edged sword.

First is the risk of liquidity “fragmentation.” Limited trading demand is spread over a longer time frame, especially since US stock trading volume during night hours is already lower than during regular hours. Extending trading hours can exacerbate thinness, leading to wider spreads, increased slippage, and higher transaction costs for retail traders. More dangerously, in a low-liquidity night environment, a small amount of capital can cause large swings, with frequent pump-and-dump phenomena.

In fact, activity during non-traditional trading hours has exploded. Data from the NYSE shows that in Q2 2025, non-trading hours volume exceeded 2 billion shares, with a transaction value of $62 billion, accounting for 11.5% of US stock trading that quarter—an all-time high. Platforms like Blue Ocean, OTC Moon, and others have seen continuous growth in night trading volumes, making night trading no longer marginal. This reflects the genuine demand from global traders, especially Asian retail investors, to trade US stocks within their own time zones.

Second is the potential shift in price discovery and market power. Nasdaq aims to re-integrate orders diverted to OTC and other off-exchange platforms back into the official exchange under the “5×23” model. However, the liquidity fragmentation problem for institutional investors remains—it’s just shifted from “off-exchange dispersion” to “on-exchange time slicing,” imposing unprecedented high costs on risk management models.

Finally, the amplification of black swan risks. Under a 23-hour trading framework, major sudden events (such as earnings misses, regulatory statements, geopolitical conflicts) can be instantly translated into trading orders. The market no longer has the buffer of “sleeping overnight to digest news,” and this immediate reaction, especially in the relatively thin night environment, can trigger chain reactions. Considering the time zone differences with Asia, a black swan event in one region could directly cause index-level volatility during US night trading hours.

This illustrates that the “5×23” model is not just a simple extension of trading hours but a systemic reconstruction of price discovery mechanisms, liquidity structures, and distribution of market power.

Tokenization Roadmap: Regulatory, Infrastructure, and Exchange Synergies

Looking further ahead, Nasdaq’s recent intensive moves reveal that this is not a sudden whim but a carefully planned strategic puzzle—aiming ultimately to enable stocks to have the same circulation, settlement, and pricing capabilities as tokens.

Nasdaq has chosen a gradual, traditional-finance-style approach, with a layered evolution:

May 2024: The first step in infrastructure upgrade. The US stock settlement cycle is officially shortened from T+2 to T+1. This may seem conservative but is actually critical. Shortening the settlement cycle begins to adapt the market to a faster capital flow rhythm.

Early 2025: Signals of extended trading hours. Nasdaq starts hinting at “around-the-clock trading” plans, preparing for the launch of continuous trading services in late 2026. Simultaneously, Nasdaq integrates Calypso systems with blockchain technology to realize 24/7 automated margin and collateral management—an invisible but clear signal to institutional investors that backend systems are ready for on-chain clearing.

Mid to late 2025: Positive institutional and regulatory developments. In September, Nasdaq formally submitted a “tokenized stock” trading application to the SEC; by November, tokenized US stocks are declared a top priority, with plans to accelerate. SEC Chair Paul Atkins also stated in interviews that tokenization is the future direction of capital markets, enabling clearer ownership rights through on-chain securities. It is expected that “within about two years, all US markets will migrate to on-chain operation, achieving on-chain settlement.”

December 2025: Submission of the 23-hour trading application. Almost simultaneously, Nasdaq submitted an application to the SEC for the 5×23-hour trading system. DTC received a no-objection letter from the SEC, approving its plan to provide real-world asset tokenization services in a controlled environment, with a planned launch in late 2026.

This timeline reveals a remarkable coordination: regulators (SEC), infrastructure (DTCC/DTC), and trading venues (Nasdaq) are demonstrating a highly synchronized rhythm in 2025. The SEC is easing regulations while signaling “full on-chain” expectations through high-level interviews; DTCC is strengthening its tokenized asset clearing and custody infrastructure; Nasdaq is advancing its tokenized stock plans front-end.

From this perspective, the 23-hour trading system is not an isolated regulatory change but a necessary step in the tokenization roadmap. Future tokenized assets will inevitably pursue 24/7 liquidity, and the current 23 hours is the closest “transitional state” to on-chain rhythm. Once investors’ trading habits are reshaped by “5×23,” patience thresholds for real-time trading and instant pricing will be raised. How far is the final goal of 7×24? Not far at all.

Final Words: Pandora’s Box Has Been Opened

As “5×23 hours” becomes the new normal, investors will inevitably ask the next question: why tolerate that one-hour interruption? Why can’t trading happen on weekends? Why can’t stablecoins be used for instant settlement?

Once human needs are unleashed, they become irreversible. When global investors’ appetite is fully lifted by 5×23, the flawed structure of traditional finance will face its ultimate challenge. Only native 7×24 tokenized assets can fill that last one-hour gap.

This is why players like Coinbase, Ondo, Robinhood, and MSX are racing—it’s not about who launches tokenized stocks first, but who can adapt faster to the “never-closing” financial future. When US stock trading hours are no longer just a matter of time, but a pointer to the entire financial system’s evolution.

The time left for the “old clock” is running out.