Nasdaq moves to make trading nearly 24 hours. Why some on Wall Street say that's a bad idea

Core Viewpoint - Nasdaq is planning to submit a proposal to the SEC for nearly 24-hour trading of U.S.-listed equities and exchange-traded products, aiming for implementation in the second half of 2026 [1] Trading Hours Expansion - The proposed trading hours would extend to 23 hours each weekday, from the current 16 hours, with a "day session" from 4 a.m. to 8 p.m. Eastern time, followed by a one-hour maintenance break, and a "night session" from 9 p.m. to 4 a.m. [2] Market Concerns - Critics argue that nearly nonstop trading could exacerbate existing issues in equity markets, such as thin liquidity, sharp price swings, and a more gamified trading environment [3] - Concerns have been raised about the impact on listed companies, as continuous trading could disrupt their ability to manage news releases and meetings without affecting market movements [4][5] Liquidity Issues - Wells Fargo noted that liquidity already clusters around market open and close, questioning the effectiveness of extending trading hours further [7] - The industry is facing skepticism regarding whether firms would need to staff trading desks around the clock to accommodate the extended hours [7][8] Purpose of Trading Pauses - Trading pauses are seen as beneficial for allowing markets to digest information and for participants to reset, with concerns that continuous trading could lead to increased volatility [8][9]