Chinanews client, August 19 (Xie Yiguan) On the 19th, the three major A-share stock indexes fluctuated downward. As of the close, the Shanghai Composite Index fell 1.24% to 3,408.13 points; the Shenzhen Component Index fell 2.09% to 13,480.85 points; the ChiNext Index fell 3.27% to 2,12.84 points. More than 3,000 shares in Shanghai and Shenzhen stocks fell, and the day's turnover exceeded one trillion. On the disk, industry sectors such as insurance, tourism, semiconductors, IT equipment, and components saw the highest declines. In terms of the conceptual sector, biological vaccines led the market, while the seed industry, artificial meat, and water conservancy construction sectors closed up against the market.