Nasdaq and NYSE Arca will launch overnight trading on Dec. 6, extending US stock sessions to at least 23 hours a day, five days a week. Nasdaq adds a session running 9 p.m. to 4 a.m. New York time, on top of regular hours and its existing pre- and post-market periods.
NYSE Arca has a similar plan, while the main exchange keeps its current hours. Both venues will pause for a nightly one-hour break for maintenance and trade processing.
The London Stock Exchange follows in 2027 with LSE 24, allowing trading in some securities from 5 p.m. until 7:50 a.m. London time.
Foreign investors are already crowding the night shift
Overnight volume in US-listed stocks sits at about 1% of the total, per the SEC. It's growing fast, with volume more than tripling in the 12 months ended August 2026.
About 37% of overnight flow comes from non-US investors, who make up roughly 10% of activity during regular hours.
Crypto and always-on prediction markets such as Kalshi and Polymarket have added pressure for traditional exchanges to stretch beyond the closing bell.
Infrastructure caught up in June, when the Depository Trust & Clearing Corp. moved to a 24x5 clearing model running Sunday evening through Friday evening.
Thin books mean wider spreads
Fewer traders after dark means lower volume and wider bid/ask spreads, which raise costs and amplify price swings.
"There's less depth. The spreads are very wide."
Jeff O'Connor, Liquidnet
The International Monetary Fund has warned that always-on, blockchain-based markets could leave regulators too little time to intervene in a crisis.
At a Sept. 17 SEC roundtable, executives flagged the need for more overnight staffing and monitoring. The same day, the SEC issued an Innovation Exemption creating a five-year pathway for venues to trade tokenized versions of US stocks.
Token holders must keep the same rights as shareholders, including dividends and votes. Companies can block tokenization of their own shares within a 30-day notice window.
Robinhood said this week it will let token holders redeem for underlying shares 1:1 and add voting rights. NYSE signed a memorandum with Blockchain.com for 24/7 trading of tokenized US equities and ETFs through a planned digital ATS, pending approval.
Blockchain.com will add NYSE data for more than 44M confirmed accounts. Demand for constant access may come from software rather than people.
Brokerages and startups are building AI agents that execute trades on behalf of retail investors, a shift one analyst expects to lift transaction volumes at least tenfold. For most retail investors, the practical change on Dec. 6 is optional, and the cost of using it shows up in the spread.
