On the morning of July 28th, the A-share market witnessed a volatile downturn, with all three major benchmark indices experiencing a synchronized decline. A notable divergence emerged between the yellow and white lines, signaling weaker performance from blue-chip stocks. Trading volume in the Shanghai and Shenzhen markets reached 1.33 trillion yuan during the morning session, marking a decrease of 21.7 billion yuan from the previous trading day. Despite the overall market downturn, over 2,800 stocks registered gains.

On the sectoral front, the brain-computer interface concept maintained its robust momentum, with Innovative Medical achieving three board hits within four trading days. The photolithography machine concept also saw a collective surge, with multiple stocks, including Zhangjiang Hi-Tech, hitting their daily limits. The consumer sector remained active, with stocks like Yiming Food also reaching their daily limits.

However, the CPO (Contract for the Difference, in this context likely referring to a specific tech or financial concept relevant to the Chinese market, though it's more commonly known in Western markets as a derivative) and memory chip concepts underwent a collective correction, with several stocks hitting their daily limits or declining by more than 10%. By the midday break, the Shanghai Composite Index had dropped 0.98%, the Shenzhen Component Index had fallen 3.42%, and the ChiNext Index had plummeted 5.37%.