Is 4 hours a day enough for A-shares?

China Securities Journal, March 13 (Zhou Yihang) — For those who monitor the markets daily, you might have this experience: busy with meetings in the morning, just about to open the app at noon to check, only to find that the A-shares market has already taken a “midday break”; in the afternoon, before the close at 3 p.m., you’re still busy with work and miss the trading opportunities, only able to regret it afterward.

After implementing 24-hour trading on trading days, the Nasdaq market in the United States recently announced plans to introduce a new tokenized stock mechanism, paving the way for future “round-the-clock” 7x24-hour trading.

Recently, the topic of “extending A-share trading hours” has attracted widespread attention. Is there room for optimization in A-share trading hours?

Global Exchanges’ Trading Hours Competition

From 9:30 to 11:30 a.m. and 1:00 to 3:00 p.m., totaling 4 hours of trading each day. This trading schedule has been used since the establishment of China’s securities market.

Looking globally, “extending trading hours” has become a choice for many exchanges.

The London Stock Exchange, Frankfurt Stock Exchange, and Euronext each have daily trading hours of 8.5 hours; Singapore Exchange’s daily trading hours are 7 hours.

Korea’s stock exchange first abolished the “midday break” in 2000, then in 2016 extended the closing time by half an hour, increasing trading hours to 6.5 hours.

Hong Kong’s Stock Exchange extended trading hours from 4 hours to 5 hours as early as 2011, and in 2012 shortened the midday break, ultimately settling at 5.5 hours.

On November 5, 2024, the Tokyo Stock Exchange will extend its closing time from 3:00 p.m. to 3:30 p.m., increasing total trading hours to 5.5 hours.

“Currently, the trading hours of A-shares are the shortest among major global markets,” said Liu Chunsheng, associate professor at the Central University of Finance and Economics. He pointed out that the current 4-hour trading window has low overlap with major global markets, which weakens China’s asset pricing power globally.

Zhao Xijun, co-director of the China Capital Market Research Institute at Renmin University of China, told China News Agency that as China’s capital market internationalizes and foreign institutional investors participate more deeply, the existing trading hours and the operation times of global capital markets are not fully aligned, which cannot fully meet international investors’ needs for time coverage.

From 13 to Over 5,400

More importantly, the A-shares market is no longer the “small scale” of the past.

In December 1990, Shenzhen and Shanghai Stock Exchanges opened one after another, with only 13 listed companies in A-shares that year. Today, A-shares are unrecognizable: daily average turnover exceeds one trillion yuan, and the number of listed companies ranks first in the world.

“By the end of 2025, the number of A-share listed companies will exceed 5,400, with over 250 million investor accounts, and daily trading volume remains in the trillions. However, the actual trading hours of only 4 hours per day can cause investors to miss trading opportunities due to time conflicts,” said Ge Yuxiang, chief analyst of non-bank financials at Zhongtai Securities, to China News Agency.

Liu Chunsheng believes that insufficient trading hours prevent market information from being reflected in prices in a timely manner. Overnight trading may lead to significant fluctuations, and it is also not conducive to smooth foreign capital allocation and risk hedging.

Technological evolution is also changing traditional trading methods. “Compared to the past reliance on offline order placement at business departments, the rapid development of quantitative and algorithm-driven intelligent trading technology is gradually becoming an important force in the market,” Zhao Xijun said. This technology-driven trading mode inherently features 24/7 operation and continuous activity, demanding higher internal flexibility in trading hours.

Regarding investor structure, the market participation is becoming more diverse. Data from the Shanghai Stock Exchange shows that by 2025, new accounts in the A-share market totaled 27.4369 million, a 9.75% increase from 24.9989 million in 2024.

Hua Xia Fund pointed out in a January 2026 article that young investors are becoming the core force of incremental individual investors, with those under 35, including “post-90s” and “post-00s,” accounting for over 45% of new accounts, becoming a vital fresh blood in the market.

Zhao Xijun said that younger investors increasingly prefer to participate in trading independently via mobile smart devices. The traditional fixed 4-hour trading period does not align well with their work and life rhythms, making it difficult for many investors to access the market conveniently during this time.

Exploring Step-by-Step Extension of Trading Hours

Extending A-shares trading hours is not a new topic. In August 2023, the China Securities Regulatory Commission explicitly stated that it would study the appropriate extension of trading hours for the A-share market and bond market to better meet trading needs.

What difficulties need to be addressed to extend A-share trading hours?

Ge Yuxiang said that extending trading hours is not simply a matter of changing the system clock but involves a comprehensive system engineering. He pointed out that “the capacity and stability of the core trading system” are the primary technical challenges. Extending trading hours means the system must operate under high load for longer periods. Whether existing matching engines and market data distribution systems can maintain millisecond-level low latency without crashes during high-frequency trading requires rigorous stress testing.

Additionally, extending trading hours involves restructuring clearing and settlement systems. Ge Yuxiang noted that “compression of end-of-day processing windows” is the biggest technical bottleneck. Currently, A-shares implement T+1 settlement, with high-intensity end-of-day clearing (including reconciliation, fund transfers, and securities transfer) typically between 3:00 and 5:00 p.m. If trading extends to 4:00 p.m. or later, the clearing window will be compressed.

Beyond technical issues, practical operation faces risks such as increased overtrading and higher operational costs. Ge Yuxiang pointed out that without changing the limit on daily price limits and T+1 settlement, extending trading hours could lead to frequent trading by some investors and increase the probability of intraday “limit-up breakouts,” raising the risk of losses for some investors.

“Moreover, the working hours of exchange staff, brokerage firms, fund companies, and bank settlement departments will be extended, increasing labor costs; at the same time, costs for data center air conditioning, electricity, and equipment depreciation will linearly increase with operational time,” he added.

Nankai University finance professor Tian Lihui told China News Agency that the current A-share market is still dominated by retail investors, who are at a disadvantage in information access and professional skills. Extending trading hours would require more effort to keep up with the market, widening the capability gap between retail and institutional investors.

Tian Lihui further said that advantages of institutions such as high-frequency trading and quantitative strategies will be amplified over longer timeframes, further squeezing retail investors’ space to survive. He believes that solving these issues should not rely solely on extending trading hours but rather on improving delisting systems, strengthening information disclosure, and guiding long-term funds into the market. Making the market more fair and transparent is more important than simply keeping it open longer.

Ge Yuxiang suggested that promoting A-shares’ openness could be done in steps. The first phase would keep morning trading hours unchanged but extend the afternoon close to 4:00 p.m., aligning with Hong Kong stocks, with minimal technical changes and the most obvious benefits (addressing linkage with Hong Kong stocks). The second phase could involve opening the market earlier at 9:00 a.m. or extending the lunch break to 12:00 p.m., increasing total trading hours to 5.5–6 hours to connect with other Asia-Pacific markets.

(More tips for reports, please contact the author Zhou Yihang: zhouyihang@chinanews.com.cn) (China News Agency App)

(The views expressed in this article are for reference only and do not constitute investment advice. Investment involves risks; please proceed with caution.)