SEC Commissioner Six asks about the 24-hour trading mechanism of the US stock market: how to ensure timely dissemination of major overnight information? Liquidity and regulatory issues still need to be answered BlockBeats News: On September 17th, SEC Commissioner Hester M. Peirce delivered a speech at the 24-hour trading roundtable meeting of the US stock market, stating that extending trading hours is taking shape in the form of a 23 hour, five-day trading week. Although some alternative trading systems (ATS) have been in existence for many years, extended trading still accounts for less than 1% of the total trading volume of NMS (National Regulated Market) stocks, and is highly concentrated in a few stocks. In the past two years, both new entrants and traditional trading platforms have been actively expanding their operating hours in response to domestic and international demand. In terms of infrastructure, NSCC has switched its clearing operations to a 24 × 5 mode in June, running continuously from 8pm on Sundays to 8pm on Fridays; The SEC has approved an extension of SIP (Securities Information Processor) operating hours, and the new schedule will be launched on December 6th; The committee also approved the implementation of the market wide limit up and limit down plan during the extended period, and the trading venue has also formulated standards to handle company actions. Peirce admitted that many market participants have conflicting attitudes towards this transformation, seeing it as an inevitable but not entirely welcomed complication, worrying about thin overnight order books, widening spreads, intensified price fluctuations, and compressed backend operations, batch processing cycles, and critical IT maintenance to only one hour per night. Peirce pointed out that there are more fundamental human concerns beyond operational issues, such as sleep. Extending trading hours will amplify concerns about data source interruptions at 3am or social media rumors suppressing stock prices while headquarters is asleep. The US market is not opening up new territories and can learn from the foreign exchange market (which has been operating 24/7 for decades), the cryptocurrency market (which never sleeps), the overnight index options and futures market (generally 23/5), and the South Korean trading platform also announced plans to extend trading hours last week. Peirce raised a series of questions: What lessons can a market with continuous trading experience provide for the US stock market regarding liquidity, market making, manipulation, and cybersecurity risks? How can brokers fulfill their best execution obligations when liquidity is dispersed and spreads are wide? Is it still acceptable for asset managers to choose not to trade overnight when liquidity and execution costs are unfavorable? Does the issuer need to change its behavior? Currently, issuers usually submit documents and release significant information before and after the core trading hours, while EDGAR files submitted after 5:30 pm are usually processed on the next business day. Does the SEC need to modify its system to ensure timely dissemination of overnight company actions and significant information? Should the committee provide guidance or relief to alleviate the burden of extended transactions on issuers, especially small issuers?