If the closing bell has long been a business model, then 24/7 trading is an attempt to break it. As the NYSE, Nasdaq, CME and Cboe race to introduce around-the-clock trading, the question is who might win and who might lose.
The answer is quite simple, Mati Greenspan, CEO and founder of Quantum Economics, told CoinDesk: “The biggest losers in 24/7 stock trading will not be traders: they will benefit massively from it. It will be the middlemen who have long made money when traders cannot trade.”
Greenspan, who is also a market analyst, argued that when markets reopen after what he called a major event, “a handful of firms set the first tradeable price. Often they will explicitly use a price that triggers stop losses for their clients, shuts them out of losses and makes a profit for the broker who is essentially trading against the client.”
When asked whether brokers coordinate prices during market closings, Greenspan was blunt in his assertion: “Yes, manipulation outright.”
“They basically get to control prices, often with hours to strategize,” he said. “Often hunting stops losses. When big news happens on the weekend, the house tends to take liberties with prices at the opening bell.”
His comments come as several major US exchanges look to offer around-the-clock trading services. The NYSE said it is 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 US index options to 24/5 trading.
‘Plausible denial’
Although Greenspan’s comments could be seen as accusatory, it is not difficult to see why such practices could be prominent in the after-hours market. When the usual opening hours end, at 16 ET, the thin liquidity can make prices easier to influence.
“After 4 p.m., you just don’t have the same liquidity,” said Joe Dente, a floor broker at the New York Stock Exchange. “People have gone home and the liquidity isn’t there, so you’re going to see wider spreads.”
Wider spreads and thinner order books, he said, create an environment where price movements can be exaggerated compared to the regular session.
Academic research also supports the view that extended trading sessions are structurally different from core 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.
Asked whether manipulation is already occurring during those periods, Dente said it is “possible,” but he also pointed out that “the event of 24-hour trading will leave things open for manipulation,” citing conditions already seen in after-hours markets.
Greenspan, meanwhile, noted that these alleged manipulation methods are “not exactly overboard, 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 occur begins to blur.
A widely cited SSRN study on open price manipulation shows how brokers can influence prices during the pre-open auction by placing and canceling large orders, temporarily pushing stocks away from their fundamental value before broader liquidity returns.
The study found that such manipulation can create distorted opening prices that are later corrected when the full market starts trading, leaving investors who bought at the inflated price with losses. Because these distortions occur before normal trading volume returns, the resulting price movements can appear indistinguishable from ordinary market volatility.
Another broker familiar with overnight trading practices, who asked not to be named because they were not authorized to speak publicly, said thin overnight liquidity can occasionally make it easier for coordinated strategies to affect prices in less-common stocks.
And this is not just anecdotal evidence.
In late 2025, the SEC settled charges over a multi-year spoofing scheme involving deceptive orders used to move prices in thinly traded securities. Regulators also fined Velox Clearing $1.3 million for failing to detect “layering” and “spoofing” in volatile stocks.
Meanwhile, the US Financial Industry Regulatory Authority (FINRA), in its 2026 Annual Regulatory Oversight Report, cited firms for “failing to maintain reasonably designed supervisory systems and controls, including with respect to identifying and reporting potentially manipulative activity conducted in after-hours trading.”
A win for retail?
Although it is difficult to point out how widespread these accusations are, one thing is certain: if trading happens 24/7, traders will be the ultimate winners, especially retailers.
In today’s electronic markets, traders who respond most quickly to market news have a structural advantage.
“There’s always an advantage to whoever has the fastest computers and the best programmers,” Dente said, noting that algorithms can respond to news and orders “in a nanosecond.” For individual investors, he added, it’s hard to keep up with that speed. “How does the human person keep up with that?”
And reacting to these events becomes even more difficult for smaller investors when the market is closed, leaving these retail or smaller traders at a massive disadvantage.
Pranav Ramesh, head of quantitative research for options at Nasdaq and co-founder of Leadpoet, said thin markets can amplify those risks.
“Broker coordination can often manifest itself as industry-wide alignment around routing and execution practices, particularly where a large portion of retail flow ends up with a small number of wholesalers,” he said. “Outside regular trading hours, monitoring can be more difficult because the market is thinner and there are fewer simple reference points for investors to benchmark execution quality,” Ramesh said in his personal capacity.
Sources familiar with broker routing and liquidity practices told CoinDesk that pricing power in thin sessions is real, especially when big news releases 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.
This is exactly what round-the-clock trading will solve for traders, according to Greenspan, who said 24/7 markets would blunt the advantage of fintech companies by removing the weekend vacuum entirely.
The recent conflict in the Middle East has been a perfect example of how this can open up more trading opportunities when markets remain closed. Decentralized exchange Hyperliquid, which trades on the blockchain 24/7, has seen increasing interest from traders betting on traditional financial assets, including oil and gold, on weekends when traditional exchanges are closed.
It has become so popular that weekly derivatives trading on the platform topped $50 billion, while generating $1.6 million in revenue over 24 hours, surpassing the entire Bitcoin blockchain’s revenue. The platform also recently added an S&P 500 perpetual contract.
Needless to say, larger exchanges are also likely to benefit from trading fees if they open for trading 24/7.
Whether 24-hour trading ultimately weakens the brokers’ influence on price setting remains to be seen. What is clear is that exchanges and investors can profit in markets that never close.
“Dealers can react in real time without being at the mercy of the middlemen — the brokers,” Greenspan said.
Read More: Bitcoin’s Weekend Sale May Be Over With CME’s 24/7 Crypto Trading Movement
