- Extended-hours trading now makes up about 10–11% of U.S. equity volume, more than doubling over the past five years.
- Many brokers have expanded access beyond pre- and after-hours to limited 24d75 trading in major stocks and ETFs.
- Execution quality is typically worse outside regular hours due to thin liquidity, wider spreads, and limits on order types and products.
- Exchanges and regulators are piloting and proposing near-24-hour weekday trading (about 22 624 hours) to meet global demand.
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Extended trading hours—periods before markets open (pre-market), after they close (after-hours), and overnight—are not just fringe windows anymore. They now contribute meaningfully to US equity markets, driven by both retail demand and institutional participation. As of early 2025, about 11% of all US equity trading volume takes place outside of the traditional 9:30am-4:00pm ET window, with average daily volumes exceeding 1.7 billion shares and daily notional value over $60 billion in aggregate.
This shift has led brokers to expand access. Firms like Interactive Brokers, Webull, Charles Schwab, and Fidelity provide extended or overnight sessions. Beyond just offering after-hours trading from 4pm-8pm ET, many are enabling trading around the clock (24 hours a day, five days a week) on select securities.,
Strategic risks remain substantial. Liquidity is uneven: post-market (4-8pm) remains dominant in notional value, but pre-market hours are growing faster. Additionally, many order flow constraints persist—limit orders only, incomplete quote visibility, delayed data reporting—all of which increase slippage risk.,
Regulators and exchanges are responding. Cboe has proposed full 24-hour trading on its EDGX exchange. NYSE-Arca aims to extend trading to 22 hours a day. These changes require infrastructure adaptation: trade reporting, corporate events, capitalization of overnight risk.,,
Strategic implications include:
- Traders may need to adapt models to account for price moves occurring outside traditional hours—any strategy ignoring pre-market or overnight could miss material returns.
- Brokers should assess potential liabilities, risk management, and system capabilities before offering 24×5 sessions broadly.
- Exchanges pursuing approval for extended hours must coordinate with data vendors, regulators, and issuers on reporting, transparency, and operational readiness.
- Institutional investors may find new opportunities in asymmetric timing of information flow and global macro events outside US core hours.
Open questions:
- How will the quality of execution evolve as volumes increase outside core hours?
- What regulatory protections are adequate for investors when order types are restricted and liquidity is thin?
- How will corporate actions—dividends, filings, earnings—be handled when markets are active overnight?
- What infrastructure—very low latency data, seamless tape reporting—will exchanges build to ensure integrity?
Supporting Notes
- Pre-market trading now accounts for over 55% of all shares traded during extended hours, up from a small fraction in 2019.,
- Extended hours represent over 11% of trading volume by share count, and over 9.8% by dollar value as of Q4 2024.
- Brokers like Charles Schwab now offer 24/5 trading on their thinkorswim platform for 1,100+ stocks and 600+ ETFs.,
- Broker access policies often restrict order types (limit orders required), disallow market orders, fractional shares, options outside regular hours.,
- In recent months, up to 25% of Robinhood’s daily volume on peak days comes from outside regular hours.
- Cboe’s EDGX early-hours trading (4-7am ET) has seen rapid growth, with about 15% of its volume in that period routed to alternate venues.
- NYSE proposed extending Arca exchange trading to 22 hours daily, from ~1:30am ET to ~11:30pm ET.