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 by more firms — 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 are moving toward extended trading hours. The SEC has granted preliminary approval for 24X Exchange and the New York Stock Exchange to operate on a 23×5 schedule; Nasdaq issued its proposal in December 2025; proposals are expected from Cboe and MEMX. The Depository Trust & Clearing Corporation’s (DTCC) National Securities Clearing Corporation (NSCC) has announced plans to support extended clearing hours by mid-2026, and three alternative trading systems (ATSs) operate in the overnight session.
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. On December 19, 2025, the SIPs submitted a Plan Amendment to the SEC to extend SIP operating hours to support overnight trading, with a target launch of December 2026 (pending SEC approval). FINRA has stated that the Trade Reporting Facilities (TRFs) will align with the SIP going forward.
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 more firms expand trading to a 23/5 model, the industry must address a range of open questions — many requiring coordination with regulators — including:
- Volatility Mechanisms: 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 of more firms 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.
