Major global stock exchanges are rapidly moving towards extending their trading hours, nearing 24 hours a day, five days a week. The NYSE Arca received SEC approval in February 2025 to extend trading to 22 hours daily, targeting a December 2026 launch. Nasdaq also secured SEC approval for its 23/5 proposal on April 10, 2026, and Cboe Global Markets filed a similar proposal for its EDGX Equities Exchange in March 2026, aiming for a December 2026 implementation. These moves by U.S. exchanges indicate a significant shift towards continuous trading, mirroring the global trend.
The London Stock Exchange Group (LSEG) announced its own initiative, LSE 24, on July 21, 2026. This new venue is designed to support near-continuous trading from Monday to Friday, operating from 5:00 PM to 7:50 AM UK time, complementing the main market's hours. LSE 24 intends to offer extended access and flexibility, with client testing expected by late 2026 and the launch of Exchange Traded Products (ETPs) in the first half of 2027, pending regulatory approval. This underscores a global structural change in equity markets, moving beyond traditional trading windows.
However, this expansion introduces challenges, especially regarding liquidity, market data, and investor protection. Currently, overnight trading sessions often feature thinner order books, wider bid-ask spreads, and a lack of consolidated market data, leading to increased volatility and potentially worse execution prices. The Depository Trust and Clearing Corporation's National Securities Clearing Corporation is targeting June 2026 to offer 24x5 settlement guarantees, a crucial step for major exchanges. The SEC is actively addressing these concerns, scheduling a roundtable for September 17, 2026, to discuss the implications of 24-hour equity markets. SEC Chairman Paul S. Atkins emphasized balancing continuous trading with investor protections. Blue Ocean ATS, a current leader in overnight ATS volume, has seen significant growth, with average volume increasing from 25 million shares per night to 250 million shares across three ATSs from June 2025 to June 2026, and a notional value exceeding $10 billion in single sessions earlier in 2026. Despite this growth, overnight trading still represents a small percentage, roughly 1%, of total U.S. equities trading volume.
