A股午评：三大指数集体下跌，深地经济概念持续活跃，黄金股回调

Market Overview - The three major A-share indices collectively declined, with the Shanghai Composite Index down 0.44% at 3899.05 points, the Shenzhen Component Index down 0.81%, and the ChiNext Index down 0.89% [1] - The total trading volume in the Shanghai and Shenzhen markets was 111.41 billion yuan, a decrease of 49.1 billion yuan from the previous day, with over 2800 stocks declining [1] Sector Performance - The industrial machinery sector continued to strengthen, with China's engineering machinery import and export trade volume in September increasing by 29.1% year-on-year; notable stocks included Iron Tuo Machinery rising over 22% and Construction Machinery and Southern Road Machinery hitting the daily limit [1] - The deep earth economy concepts, including combustible ice and shale gas, remained active, with Shen Kai Co. and Petrochemical Machinery achieving three consecutive daily limits, and Petrochemical Oil Services hitting the daily limit [1] - Real estate stocks rose against the trend, with Yingxin Development achieving three consecutive daily limits and Tianbao Infrastructure and Guangming Real Estate hitting the daily limit; an article from Economic Daily emphasized the need for efforts to stabilize the real estate market [1] - The plant-based meat concept stocks saw a general rise, with Shuangta Food hitting the daily limit and Suobao Protein rising over 8%; Beyond Meat, the "first stock of plant-based meat" in the US, surged 450% over two days [1] Declining Sectors - Gold stocks collectively retreated, with Hunan Silver down over 8%, and Silver Nonferrous and Western Gold down over 6%; gold prices experienced the largest single-day drop in 12 years, barely holding above $4000 [1] - The battery sector faced significant declines, with Fangyuan Co. down over 9%, and Boliview and Haike New Source down over 7% [1]