US stock market opening hours extended to 23 hours: How is Nasdaq approaching the limit of "sleepless finance"?

As the 7×24 trading model in the crypto market gradually becomes the global norm, the limitations of traditional stock markets are increasingly evident. Recently, Nasdaq submitted an application to the U.S. Securities and Exchange Commission (SEC) planning to significantly expand U.S. stock market opening hours, from the current 5 days a week, 16 hours a day (including pre-market, regular trading, and after-hours trading), to 5 days a week, 23 hours a day, with only 1 hour reserved for system maintenance and settlement. Behind this move lies a strategic intent far deeper than simply “convenience for Asian investors.”

Once approved, U.S. stocks will trade continuously from 21:00 on Sunday to 20:00 on Friday, with only a 1-hour interruption each day. The superficial reason is to meet the trading needs of global cross-timezone investors, but in essence, this is Nasdaq conducting an extreme stress test for the upcoming tokenization of stocks and on-chain clearing systems.

The Practical Dilemma of Expanding Trading Hours: The “Achilles’ Heel” of Traditional Financial Systems

From the evolution logic of U.S. stock market opening times, this expansion is not merely a rule adjustment but a profound overhaul of the entire financial infrastructure. Extending the market from 16 to 23 hours effectively pushes the existing centralized clearing and settlement system to its physical limits.

Participants in traditional financial markets—including exchanges, brokerages, clearing agencies (like DTCC), regulators, and listed companies—must upgrade their systems accordingly. Specifically:

Operational Pressure Escalation: Brokerages need to extend trading maintenance, risk control, and customer service to operate around the clock, significantly increasing manpower and technical costs. Clearing agencies must extend settlement systems into the early morning hours (e.g., until 4 a.m.) to accommodate the new “next-day after-hours settlement” rules. Listed companies face new challenges—revising the timing of financial reports and major disclosures, as key information will be priced by the market in non-traditional hours.

The Deep Meaning of the 1-Hour Downtime Window: Why set a daily 1-hour market closure instead of pushing for 24/7 trading? The answer lies in the existing architecture of DTCC and commercial banking systems, which must reserve physical downtime for end-of-day data processing, account reconciliation, and margin settlement—similar to banks’ end-of-day balancing. Although this incurs significant operational costs, it provides necessary buffers for fault isolation, data synchronization, and risk management.

However, this remaining 1 hour in the future demands nearly stringent cross-role coordination within the industry. In contrast, blockchain-based crypto assets, with distributed ledgers and atomic settlement via smart contracts, inherently support 7×24×365 trading without closing, no market hours, no market halts, and no end-of-day windows—precisely why traditional exchanges are forced to challenge these limits.

Market Structure Concerns: Liquidity Fragmentation and Black Swan Risks

On the surface, extending U.S. stock market hours seems beneficial for cross-timezone investors, especially retail traders in Asia. According to NYSE data, in Q2 2025, trading volume during non-traditional hours (pre-market and after-hours) exceeded 2 billion shares, with a trading value of $62 billion, accounting for 11.5%, reaching a record high. This clearly indicates that global investors’ demand to “trade U.S. stocks in their own time zones” has exploded.

However, the release of demand does not necessarily improve price discovery quality. On the contrary, the “5×23 hours” model may act as a double-edged sword:

Liquidity “Fragmentation” Trap: Although extending trading hours theoretically attracts more capital, in reality, limited trading demand is spread over a longer period. Night trading volumes are already much lower than regular hours; extending hours can lead to wider bid-ask spreads, reduced liquidity, increased trading costs, and heightened market volatility. During low-liquidity periods, large funds can more easily manipulate prices or cause abrupt sell-offs.

Dispersed and Reconstructed Price Discovery Power: Nasdaq attempts to “bring back” trading that was previously diverted to OTC platforms like Blue Ocean and OTC Moon through the “5×23 hours” model. But for institutions, liquidity fragmentation remains unresolved—it’s merely shifting from “off-exchange dispersion” to “on-exchange time-slicing.” This imposes higher technical and cost demands on risk management and large order execution.

Immediate Amplification of Black Swan Events: Under the 23-hour trading framework, any major sudden event—be it earnings surprises, regulatory changes, or geopolitical conflicts—will be instantly converted into trading orders, removing the buffer of “overnight digestion.” In low-liquidity night sessions, such instant reactions can trigger gaps, sharp volatility, and even irrational chain liquidations, magnifying the destructive power of black swans in the absence of counterparties.

A Grand Strategy: U.S. Stock Market Opening Time Reform as a Prelude to Tokenization

Looking further ahead, Nasdaq’s actions over the past year reveal a tightly interconnected strategic puzzle ultimately pointing toward stock tokenization and on-chain trading.

Evolution of the Timeline: In May 2024, U.S. stock settlement systems were shortened from T+2 to T+1. While seemingly conservative, this is a critical infrastructure upgrade. Early 2025, Nasdaq began signaling “all-day trading” and plans to launch continuous trading services in the second half of 2026. More covertly but equally important, Nasdaq’s Calypso system has integrated blockchain technology for 7×24-hour automated margin and collateral management—imperceptible to ordinary investors but a clear signal to institutions.

High-Level Coordination of Regulation, Infrastructure, and Exchanges: SEC Chairman Paul Atkins explicitly stated in interviews that tokenization is the future of capital markets. By bringing assets on-chain, clearer ownership rights can be achieved. He predicts that “within 2 years, all U.S. markets will migrate on-chain, achieving on-chain settlement.” Meanwhile, DTC (Depository Trust & Clearing Corporation), a subsidiary of DTCC, received SEC approval on December 12 to provide real-world asset tokenization services, planning to launch in late 2026. Nasdaq has also announced plans for tokenized stocks, prioritizing this initiative.

The synchronized actions of regulators, clearing infrastructure, and exchanges on this timeline indicate this is no coincidence but a highly coordinated systemic project. The expansion of U.S. stock market hours is essentially a “transitional phase” designed to support the pursuit of 7×24 global liquidity for tokenized assets.

The Final Sprint: From “5×23” to “7×24”—An Inevitable Path

Once human needs are unleashed, they are hard to reverse. After investors adapt to the 23-hour U.S. stock market model, they will inevitably ask: Why tolerate that 1-hour break? Why can’t trading happen on weekends? Why not settle instantly with stablecoins?

As global investors’ expectations are raised by the “5×23 hours” model, the existing traditional financial architecture will face ultimate disintegration, leaving only native 7×24 on-chain tokenized assets to fill that final gap. This is precisely why players like Coinbase, Ondo, Robinhood, and others are racing—those who lag behind will be swallowed by the on-chain wave.

From the reform of U.S. stock market opening hours, we see not just a rule change but the final countdown of the global financial system.