If the closing bell has long been a business pattern, then 24/7 trading is an attempt to break it. As the NYSE, Nasdaq, CME and Cboe work to introduce 24-hour trading, the question is who stands to gain and who stands to lose.
The answer is quite simple, Mati Greenspan, CEO and founder of Quantum Economics, told CoinDesk: “The biggest losers in 24/7 stock trading won’t be the traders: they will benefit massively. It will be the middlemen who have long made money when traders can’t trade.”
Greenspan, also a market analyst, said that when markets reopen after what he calls a big event, “a handful of firms decide the first tradeable price. Often, they will explicitly use a price that triggers stop losses for their clients, closing them at a loss and making a profit for the broker who is essentially trading against the client.”
When Greenspan was asked if brokers were coordinating around prices during market closures, he was blunt in his response: “Yes, pure and simple manipulation.” »
“They basically control prices, often with hours to strategize,” he said. “Often, chasing stops the losses. When big news breaks on the weekend, the house tends to take liberties with prices at the opening bell.”
His comments come as several major U.S. exchanges seek to offer 24-hour trading services. The NYSE said it was seeking SEC approval for 24/7 trading. Nasdaq announced similar plans in December. CME plans to roll out 24-hour crypto futures in 2026, pending approval, and Cboe recently expanded U.S. index options to 24/5 trading.
“Plausible deniability”
Although Greenspan’s comments could be seen as accusatory, it is not difficult to understand why such practices might be prevalent in the after-hours market. When regular trading hours end, at 4 p.m. ET, low liquidity can make prices easier to influence.
“After the 4 p.m. bell, you just don’t have the same liquidity,” said Joe Dente, a stockbroker at the New York Stock Exchange. “People have gone home and the liquidity is not there, so spreads will widen.”
Wider spreads and tighter order books, he said, create an environment in which price movements can be exaggerated compared to the regular session.
Academic research also supports the idea that extended trading sessions are structurally different from main market hours. A widely cited joint UC Berkeley-University of Rochester study found that after-hours price discovery is “much less effective,” citing lower volume and thinner liquidity that limit the speed at which information is incorporated into prices.
When asked if manipulation was already occurring during these periods, Dente said it was “possible,” but he also pointed out that “the 24-hour trading event is going to leave things open to manipulation,” referring to conditions already seen in after-hours markets.
Greenspan, meanwhile, noted that these alleged manipulative practices “are not entirely honest, so they [brokers who might be taking part in such actions] tend to maintain plausible deniability.
This is where the line between actual manipulation and proof that such practices are taking place begins to blur.
A widely cited SSRN study on opening price manipulation shows how brokers can influence prices in pre-open auctions by submitting and canceling large orders, temporarily moving stocks away from their fundamental value before broader liquidity returns.
The study found that such manipulation can create distorted opening prices that are then corrected once the market begins trading, leaving investors who bought at the inflated price to suffer losses. Because these distortions occur before trading volume returns to normal, the resulting price movements may appear indistinguishable from ordinary market volatility.
Another broker, familiar with day-to-day trading practices and who asked not to be named because he was not authorized to speak publicly, said that low day-to-day liquidity can sometimes make it easier for coordinated strategies to influence the prices of less widely traded stocks.
And it’s not just anecdotal evidence.
In late 2025, the SEC settled charges relating to a multi-year impersonation scheme involving deceptive orders used to move prices of thinly traded securities. Regulators also fined Velox Clearing $1.3 million for failing to detect “layering” and “spoofing” in volatile stocks.
At the same time, the Financial Industry Regulatory Authority (FINRA), in its 2026 annual regulatory oversight report, cited the companies for “failing to maintain reasonably designed supervisory systems and controls, including with respect to the identification and reporting of potentially manipulative activities conducted after hours.”
A victory for retail?
Although it is difficult to emphasize the magnitude of these accusations, one thing is certain: if trading occurs 24/7, traders will be the ultimate winners, especially retail traders.
In today’s electronic markets, traders who react most quickly to market news have a structural advantage.
“Whoever has the fastest computers and the best program writers will always have an advantage,” Dente said, noting that algorithms can respond to news and commands “in a nanosecond.” For individual investors, he added, it is difficult to keep up with this pace. “How can the human person follow this?
And reacting to these events becomes even more difficult for small investors when the market is closed, putting retail or small traders at a massive disadvantage.
Pranav Ramesh, head of quantitative options research at Nasdaq and co-founder of Leadpoet, said tight markets can magnify these risks.
“Broker coordination can often manifest as industry-wide alignment around routing and execution practices, particularly when a large portion of the retail flow results in a small number of wholesalers,” he said. “Outside normal hours, monitoring can be more difficult because the market is smaller and there are fewer simple benchmarks for investors to assess the quality of execution,” Ramesh said in his personal capacity.
Sources familiar with brokers’ routing and liquidity practices told CoinDesk that the pricing power in thin sessions is real, especially when major news breaks while markets are closed. According to these sources, coordination around routing, spreads and execution practices during extended gaps has historically been easier precisely because retail traders cannot participate.
That’s precisely what 24-hour trading will solve for traders, according to Greenspan, who said 24/7 markets will blunt fintech firms’ advantage by completely removing the weekend vacuum.
The recent conflict in the Middle East is a perfect example of how this can open up more business opportunities when markets remain closed. Decentralized exchange Hyperliquid, which trades on the blockchain 24/7, has seen growing interest from traders betting on traditional financial assets including oil and gold over the weekend when traditional exchanges are closed.
It became so popular that the weekly derivatives trading volume on the platform exceeded $50 billion, while generating $1.6 million in revenue over 24 hours, surpassing the revenue of the entire Bitcoin blockchain. The platform also recently added an S&P 500 perpetual contract.
It goes without saying that major exchanges will also likely benefit from trading fees if they are open 24/7.
It remains to be seen whether 24-hour trading will ultimately weaken brokers’ influence over pricing. What is clear is that stock markets and investors stand to gain from markets that never close.
“Traders can react in real time without being at the mercy of middlemen, brokers,” Greenspan said.
Read more: Weekend Bitcoin sell-off could be over with CME’s 24/7 crypto trading move
