For most of a century, the American stock market has had a hard stop. At 4:00 p.m. Eastern time, the closing bell rings, the tape stops, and a trader in Singapore or Tokyo who wants to move on a headline must either wait for the next morning or pay a premium in a thin after-hours market. That rhythm is now being dismantled, and the machinery doing it is no longer experimental.
Nasdaq has filed with the Securities and Exchange Commission to trade equities and exchange-traded products 23 hours a day, five days a week. The regulator approved the plan in April. Under the new schedule, a day session runs from 4:00 a.m. to 8:00 p.m. Eastern, and a night session picks up from 9:00 p.m. to 4:00 a.m. In between sits a single hour, from 8:00 to 9:00 p.m., when the exchange shuts down for maintenance, corporate-action processing, and the kind of systems work that used to happen every single night.
The New York Stock Exchange is moving on a parallel track. Its Arca venue won approval in February 2025 to run 22 hours a day on weekdays, and the exchange has signaled it is exploring a round-the-clock platform for tokenized securities, working with the firm Securitize. Nasdaq has paired with Payward, the parent of the crypto exchange Kraken, on tokenized trading. The direction is the same on both sides of the street: the market’s hours are being pulled toward the 24/7 schedule that cryptocurrencies have run since the beginning.
The pressure to do this came from two directions at once. Institutional investors in Asia and Europe want to trade U.S. stocks on their own clocks instead of waking up at midnight. And the exchanges watched order flow leak to crypto venues and overseas platforms that never close. If the incumbent exchanges did not extend their hours, the argument went, the business would eventually go somewhere that already had.
Retail and institutional demand for after-hours access has grown sharply. Brokers that once offered night trading to a small sliver of clients now advertise it broadly. Nasdaq’s own filing cites the use of digital-asset platforms that trade 24/7 as a reason it must compete for order flow. The exchanges are not so much creating a new market as conceding that one already exists and choosing to own it.
The shift comes with costs that the exchanges have been slower to advertise. Liquidity in the overnight sessions is thinner than in the regular day, which means wider spreads and more room for a single large order to move a price. Volatility that used to be confined to the 9:30 open can now arrive at 2:00 a.m. Critics inside the industry, including some asset managers, have warned that a market that never closes is also a market where bad news can compound without a pause, and where the humans paid to watch risk must now work in shifts around the clock.
Clearing and settlement have to change too. A trade is not finished when the price prints; it is finished when the cash and the shares move. Extending the trading day to 23 hours forces the back offices that settle those trades, and the consolidated data feeds that report the prices, to run on the same schedule. The Securities Information Processors, which supply the official consolidated tape, have only begun proposing their own extensions, which is why the exchanges describe these moves as launches in progress rather than done deals.
The SEC itself has pushed the conversation into the open. In September it convened a roundtable in Washington on round-the-clock trading and tokenized stocks, listening to what the rebuild requires without adopting a rule that day. The regulator has already approved extended hours for Nasdaq, NYSE Arca, and the upstart 24X National Exchange, which won clearance in late 2024 to trade 23 hours a day.
The tokenized piece of the plan is the part that most worries the industry’s critics. Nasdaq and NYSE are not just extending the hours of the existing market; they are attaching the machinery of a stock exchange to the infrastructure of crypto, where assets move around the clock and settlement can be nearly instant. In March, the SEC cleared Nasdaq to trade tokenized securities alongside conventional shares, with settlement running through a pilot at the Depository Trust Company. The result is a market that begins to look like two markets sharing one ticker.
For the exchanges, the economics are straightforward. Fitch has written that longer trading days will lift revenue and risk profiles for the operators. For the investors, the change is more ambivalent: more hours to react, fewer hours to breathe. The market that once closed at 4:00 p.m. and stayed closed until morning is on its way to a schedule closer to a casino’s, and the main thing left to decide is which hour of the night becomes the new 9:30.
