SEC Asks Firms to Help Plan 24-Hour U.S. Stock Trading

The Securities and Exchange Commission has asked BlackRock, Robinhood, the New York Stock Exchange and a group of asset managers, broker-dealers, exchanges, clearing firms and market makers to help design a plan for 24-hour trading of U.S. stocks. The firms will work with SEC staff to assess how around-the-clock trading could be implemented.

The review will examine the operational, technical and regulatory steps needed to expand trading beyond the current regular session and existing pre-market and after-hours sessions. SEC staff have asked participating firms to identify what changes would be required to systems, rules and industry protocols.

Participants are expected to evaluate how continuous trading could affect liquidity and price discovery, and how market surveillance and enforcement would operate on a 24-hour basis. The group will also consider impacts on clearing and settlement, fund operations and net asset value calculations for asset managers and ETF issuers, and order routing, investor protections and retail access for brokers and trading platforms. Exchanges will examine trading rules and market data distribution under an extended schedule.

Officials and industry representatives have highlighted practical concerns the group will need to address. Extending hours could require longer staffing shifts at exchanges and clearinghouses, upgrades to market data and surveillance systems, adjustments to settlement processes and changes in how broker-dealers manage overnight risk. The review will also consider whether liquidity outside core hours would be deep enough to support orderly prices and whether trading could become more fragmented across venues.

The SEC framed the effort in the context of rising retail trading activity and demand for round-the-clock access, and pointed to existing 24-hour trading in other products such as futures and cryptocurrencies. U.S. equities already trade in limited pre-market and after-hours sessions, which account for a small share of overall volume and typically show thinner liquidity and wider spreads than the regular session.

The working group is intended to gather practical input before any formal rulemaking is proposed. The SEC will consider the group’s findings and any industry recommendations as it decides if and how to change rules or adopt new industry protocols. Background material notes the core U.S. equity trading day runs from 9:30 a.m. to 4:00 p.m. Eastern time, and that a move to continuous 24-hour trading would require notable operational and regulatory changes.