Extended Trading Hours

U.S. equity markets are advancing toward near “round-the-clock” trading, providing global investors with unprecedented access and liquidity. This shift — to 23 hours a day, five days a week — represents a major structural evolution that will impact trading strategies, infrastructure, risk management, and operations across the industry.

National securities exchanges including NYSE, Nasdaq, and Cboe are moving toward extended trading hours, and the SEC has granted preliminary approval for 24X Exchange to operate on a 23×5 schedule. The Depository Trust & Clearing Corporation’s (DTCC) National Securities Clearing Corporation (NSCC) has announced plans to support extended clearing hours by mid-2026, and several alternative trading systems (ATSs) already offer expanded sessions.

On May 6, 2025, the Operating Committees of the Securities Information Processors (SIPs) announced plans to extend SIP operating hours from 8:00 p.m. ET Sunday through 8:00 p.m. ET Friday, with a one-hour technical pause Monday–Thursday from 8:00–9:00 p.m. ET.

This proposal aligns market data dissemination with the broader push for nearly continuous trading and reflects key recommendations advanced by SIFMA and its members.

Key Focus Areas

Establishing Standard Market Hours

SIFMA recommends a consistent market structure built around three foundational elements:

Trade Date End: The U.S. trade date should end at 8:00 p.m. ET (e.g., trades between 8:00 p.m. and midnight Monday will have a Tuesday trade date and Wednesday settlement).
Exchange Hours: Exchanges operate 23 hours a day, five days a week, from Sunday 9:00 p.m. ET to Friday 8:00 p.m. ET.
Maintenance Window: A daily one-hour pause from 8:00–9:00 p.m. ET provides time for processing, reconciliation, and system resilience.

Aligning start and end times across exchanges and ATSs is critical for efficiency, coordination, and operational readiness.

Supporting Industry Flexibility

Participation in the extended window should remain optional, allowing firms to align investment in infrastructure and staffing with client demand and business strategy.

Addressing Operational and Regulatory Implications

As trading expands to a 23/5 model, the industry must address a range of open questions — many requiring coordination with regulators — including:

Market Rules & Governance: Circuit breakers, halts, and volatility controls suited for continuous sessions.
Trade Reporting & CAT: Adjustments to real-time reporting, timestamps, and session identifiers.
Supervision & Best Execution: Updates to supervisory coverage and execution standards during lower-liquidity periods.
Settlement & Corporate Actions: Standardized treatment of record dates, cut-offs, and overnight processing.
Cyber & Operational Resilience: 24-hour monitoring, incident response, and risk management coverage.

Preparing for Implementation

Firms should begin evaluating the impact of extended trading on business models, operations, and infrastructure by:

Monitoring regulatory and exchange guidance.
Assessing client demand and readiness.
Reviewing risk management, liquidity, and credit frameworks.
Coordinating with vendors and third-party service providers.
Establishing firm-wide governance for implementation planning.

Convening Industry Coordination

SIFMA, in collaboration with DTCC, exchanges, and industry stakeholders, is leading working groups focused on:

Clearing and settlement
Market structure and volatility mechanisms
Corporate actions and trade reporting
Margin, risk management, and supervision

These efforts aim to align operational standards, ensure market integrity, and support a seamless industry-wide transition.

The Bottom Line

The move toward 23/5 trading is a defining step in the modernization of U.S. equity markets. With opportunity comes complexity — and the success of this transition will depend on thoughtful coordination across the industry and with regulators.

SIFMA is committed to ensuring this evolution strengthens market efficiency, transparency, and resilience for all participants.

Extended Trading Hours: A New Frontier for US Equity Markets

U.S. equity markets are advancing toward near “round-the-clock” trading, aiming to provide global participants with unprecedented extended hours access to U.S. equities markets. This evolution presents a significant shift that will impact trading strategies, infrastructure, risk management and operational models for all market participants operating during extended trading hours.