Major US stock exchanges are exploring the prospect of keeping equity markets open around the clock, seven days a week—an unprecedented shift that could fundamentally transform how American investors trade. The proposal, which involves prominent marketplaces like NYSE, Nasdaq, CME, and Cboe, would break with longstanding Wall Street conventions by allowing continuous trading beyond traditional session hours. This potential evolution has reignited discussions around the implications for both market participants and financial intermediaries.
The impact of uninterrupted trading on investors
Mati Greenspan, founder and CEO of Quantum Economics, believes that moving to 24-hour trading would be especially advantageous for individual investors. He points out that brokers have historically benefitted from after-hours market closures, exploiting these windows to determine prices and profit from investor losses. Moreover, Greenspan notes that when major news breaks during weekends or holidays while markets remain closed, only a handful of institutions are able to influence opening prices—sometimes to the detriment of ordinary investors.
Greenspan commented that prices are more easily influenced when markets are closed, sometimes resulting in sharp opening volatility after significant weekend developments.
Sparse liquidity outside of normal sessions has often exaggerated price movements in after-hours trading. Joe Dente of the New York Stock Exchange highlights that with lower transaction volumes during these times, bid-ask spreads tend to widen, intensifying volatility. This lack of liquidity can leave traders exposed to more erratic price swings than during regular hours.
Academic studies also reveal that price discovery is less efficient outside standard trading sessions. Joint research from UC Berkeley and the University of Rochester finds that thin volume and restricted liquidity during off-hours slow the incorporation of new information into stock prices.
Manipulation concerns and regulatory response
As continuous trading becomes a serious consideration, concerns are resurfacing regarding volatility and potential manipulation during hours when markets have traditionally been closed. Dente warns that the risks of manipulation could persist, or even intensify, in a 24-hour marketplace since thin liquidity makes it easier to move prices artificially.
A recent SSRN study has documented cases in which some brokerages submitted large buy or sell orders just before markets opened, only to cancel them before execution—an approach designed to move prices higher or lower artificially. In response, the US Securities and Exchange Commission (SEC) has recently fined firms like Velox Clearing millions of dollars for using misleading orders to create price swings.
Regulators have stressed the importance of robust oversight mechanisms, especially outside of regular trading hours. The Financial Industry Regulatory Authority (FINRA) has called for improved surveillance and reporting systems to mitigate risks associated with continuous trading.
Market analyst Pranav Ramesh agrees that off-hours markets are more vulnerable and prone to erratic price action, making it harder for retail investors to find reliable pricing benchmarks. He notes that when major events occur while markets are closed, brokers gain a disproportionate role in price-setting at the next opening.
Uninterrupted trading platforms based on cryptocurrency and blockchain technologies have surged in popularity, particularly during periods of increased global turmoil. The decentralized Hyperliquid platform, for instance, reportedly surpassed $50 billion in weekly derivatives volume and achieved $1.6 million in daily income, driven in part by its recent launch of perpetual futures tied to the S&P 500 index.
