Extended trading could change everything from staffing models to market volatility. What happens when a bank collapses at 1 a.m.? By David Wignall

Wall Street employees agree that 24-hour trading is inevitable. That doesn't mean they're happy about it.

For years, investors hoping to trade U.S. equities on major exchanges were confined to the traditional hours of 9:30 a.m. to 4 p.m. ET, five days a week. Some exchanges also offered "extended hours," starting at 4 a.m. and ending at 8 p.m.

But soon, round-the-clock equity trading will be the new normal. The New York Stock Exchange, Nasdaq, and the London Stock Exchange are all weighing plans to extend weekday trading deep into the night. Robinhood Markets, Interactive Brokers, Firsttrade, and Charles Schwab all already offer 24-hour trading five days a week for many stocks. And a key market infrastructure provider, the Depository Trust & Clearing Corp., says it is preparing to accommodate round-the-clock trading as soon as the second quarter of 2026.

For now, the weekend is still off limits. But finance professionals across Wall Street are watching the advance of 24-hour trading with trepidation. They wonder: Will asset managers need to staff their offices at midnight? Will nighttime liquidity harm retail investors? What happens if a bank collapses at 1 a.m.?

Jenny Hadiaris, head of North America electronic execution at Citigroup, says that while retail clients are excited about round-the-clock trading, "institutional investors have been a lot more tepid on this." She adds, "It's a huge lift. It's a massive lift for the Street."

Financial advisors also see potential trouble ahead. "Imagine going through Covid-19, the fastest drop in history, with a market that never closes," says Peter Mallouk, president of Creative Planning, a large wealth manager. "We are not staffed for round-the-clock client assistance."

The Push for Round-the-Clock

Exchanges are moving to round-the-clock trading for many reasons. They want to cater to Asian retail investors, who are increasingly interested in big-name U.S. stocks like Nvidia and Microsoft. They are following the lead of cryptocurrency and commodities markets, which already trade continuously. And they want to encourage more foreign companies to list their stocks in the U.S.

Some wonder whether the appetite is even there. Just 11% of overall trading volume in 2025 took place outside the traditional 9:30 a.m. to 4 p.m., according to Nasdaq. Trading from 8 p.m. to 4 a.m. is even thinner, accounting for only 0.2% of total volume.

But some traders and exchanges are hoping that NYSE and Nasdaq's moves will induce additional activity. "Us coming into the market will likely unlock additional demand," says Chuck Mack, senior vice president for North American markets at Nasdaq.

If that demand materializes, it could be a tremendous boon for traders and exchanges, since both typically profit when more people are buying and selling stocks. But when there is no closing bell, it could also disrupt life on Wall Street. "It doesn't matter what your view is," says Hadiaris. "There's pros. There's cons. It doesn't matter -- it's coming."

Wide Spreads and Flash Crashes

In conversations with Barron's, more than a dozen financial professionals voiced a variety of concerns regarding the impact of 24-hour trading -- though they also stressed that the change is inevitable.

Many worry about liquidity and execution. When few participants are trading, market makers must hold on to shares for longer. To compensate for the increased risk, they widen their bid/ask spreads -- the gap between the cost of buying and selling shares. At night, when almost no one is trading and not all market makers are offering their services, spreads can be unusually wide.

If unsuspecting investors place orders at night when spreads are broad, they will effectively receive worse prices than if they wait for daylight.

"A lot of people don't realize that they're likely to do far worse in terms of price if they're going to trade overnight," says Benjamin Schiffrin, director of securities policy at Better Markets, an advocacy group. Schiffrin believes that if overnight trading is conducted on exchanges, spreads could narrow somewhat, but far more retail investors would be exposed to the risks.

Low liquidity wouldn't just harm individual investors. If an investor places a large sell order and there are few buyers available, prices could fall, potentially triggering additional automated selling. "There could be many flash crashes," says Lynn Challenger, global head of trading at UBS asset management. When the market is thin, anybody buying or selling at the wrong moment could lose their shirt.

In the short term, many trading experts expect liquidity to be extremely thin between 8 p.m. and 4 a.m. But volumes could pick up when big events occur, like a presidential election or geopolitical crisis.

Pressure on People and Plumbing

Many traders and investors have come to appreciate the closing bell. After 4 p.m., they have ample time to clean up their books, meet with co-workers, schmooze with clients, and grab some sleep. While asset prices technically move overnight, the tape is out of sight and volume is thin.

In a continuously trading world, stock-price movements would always be in view. "I think for the equities traders, it'll be a new level of stress and anxiety because they will never get a break," says John Shammas, chief growth officer at DriveWealth, a financial-technology company that helps investors operate overnight. "For the futures and options traders, they're used to this" because those assets already trade at nearly all hours.

Investors who enjoy an evening cocktail aren't the only ones who rely on the closing bell. Currently, exchanges and brokers use the dead of night to handle a host of rarely thought-of functions. Trades must be settled, closing prices recorded, stocks split, mistakes reversed, and dividends paid. In a round-the-clock world, it's still unclear how the market plumbing will operate.

"Most broker-dealers are used to having a six-plus-hour period when they can do all their corporate action processing," says Shammas.

Staffing is an obvious issue. "If the market's going to be open, regardless of whether there's a lot of liquidity or not, it could create price risk for investors," says Michael Cyprys, an equity analyst at Morgan Stanley. Someone will need to be awake to manage that risk, at least at firms with demanding clients.

The Securities Industry and Financial Markets Association, a trade group, noted in a Securities and Exchange Commission filing that "overnight on-exchange trading will require additional staffing at regulators, firms, and third-party service providers" to monitor systems and respond to clients. The trade group asked: "Who pays for these increased costs?"

Those costs could fuel further consolidation. Many large traders and asset managers already have staff awake at all hours. If a price moves while New York is asleep, employees in Singapore are able to respond. But smaller firms without global presences will be out of luck.

Who Will Benefit?

Many finance professionals are also wondering what might happen when market-shifting news happens during the wee hours. On the one hand, overnight exchange trading will allow more asset managers to respond to events in real time, so their portfolios will always reflect their views on current information. On the other, overnight trading -- especially when more retail investors get involved -- could cause investors to respond impulsively. Rather than waiting until morning, when cooler heads may prevail, investors could jump into the fray right away.

"It heightens the probability that you get an emotional response to market events," says Kristi Mitchem, a founder of wealth manager &Partners who was previously CEO of Wells Fargo asset management.

If investors react impulsively, the people who benefit will be the professionals: the hedge funds, proprietary traders, and algorithmic funds who already dominate pre- and postmarket trading and can take advantage of irrationally priced assets.

"My view of 24-hour trading is it has little benefit," says Victor Haghani, a wealth manager who co-founded Long-Term Capital Management. "It's just going to facilitate a greater redistribution of wealth from retail speculators to proprietary traders."

The rise of 24-hour trading could also privilege high-speed, computerized operations. Under the current system, there is little benefit to reading a news release at 8 p.m. as opposed to 8:05 p.m. All investors have to wait until the morning to place their trade, giving everyone ample time to receive and digest information. But if the exchanges are open when news arrives, reaction time may become more important. Using machine learning and web scraping tools to consume information -- already par for the course for some funds operating in the daytime -- could become even more important.

A senior trading executive at a large U.S. bank noted that overnight trading could exacerbate market contagion. The executive observed that, during the collapse of Bear Stearns in March 2008, regulators and executives had several nights and a weekend to organize a bailout and sale of the beleaguered bank. That breathing room may soon be in short supply.

"Imagine if when GameStop was happening, the markets were open 24/7," says Better Markets' Schiffrin. "I think it was hard enough for the SEC and others to understand what was transpiring in the market then."

Skeptical of the benefits and wary of thin liquidity, many investors say they are planning to stay away from overnight trading and expect others to do the same. "Buy-and-hold and institutional investors would probably sit on the sidelines," says Michael Arone, chief investment strategist at State Street.

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October 24, 2025 21:31 ET (01:31 GMT)

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