Core Viewpoint - The trading volume in A-shares is heavily concentrated in the first half hour of the morning session, accounting for approximately 25% to 32% of the total daily trading volume, due to factors such as the T+1 trading system, information release patterns, and investor behavior [1][4][10]. Group 1: Trading Volume Concentration - A-shares see significant trading activity in the first half hour of the morning, which can represent up to one-third of the total daily volume [1][4]. - Other notable trading peaks occur shortly after the afternoon session opens and just before the market closes, collectively accounting for nearly half of the daily trading volume [4][14]. Group 2: Reasons for Trading Patterns - The T+1 trading system restricts investors to one trading opportunity per day for each stock, leading to a heightened focus on timing, with most choosing to trade in the morning [7][11]. - Information is primarily released after market close, prompting investors to react quickly the next morning, which drives concentrated trading activity in the early session [8][10]. - Institutional investors prefer to trade during busy periods to minimize the impact on stock prices, further amplifying the trading volume during the first half hour [11][14]. Group 3: Afternoon Trading Peaks - The first 15 minutes after the afternoon session begins sees increased trading as investors reassess the morning's performance and react to any new information released during the lunch break [14]. - The last 10 minutes before market close is characterized by cautious investors making final decisions based on the day's observations, either to secure positions or mitigate risks [14].