化学原料板块9月18日跌1.71%，世龙实业领跌，主力资金净流出8.58亿元

Market Overview - On September 18, the chemical raw materials sector declined by 1.71%, with Shilong Industrial leading the drop [1] - The Shanghai Composite Index closed at 3831.66, down 1.15%, while the Shenzhen Component Index closed at 13075.66, down 1.06% [1] Stock Performance - Notable gainers included *ST Yatai, which rose by 4.99% to a closing price of 9.04, and Zhenhua Co., which increased by 1.95% to 18.34 [1] - Major decliners included Shilong Industrial, which fell by 5.22% to 9.45, and Dayang Biology, which decreased by 5.09% to 33.20 [2] Trading Volume and Value - The trading volume and value for selected stocks in the chemical raw materials sector showed significant activity, with Huajin Technology recording a trading value of 873 million and Luyin Investment at 82.33 million [1][2] - The overall net outflow of main funds in the chemical raw materials sector was 858 million, while retail investors saw a net inflow of 615 million [2] Fund Flow Analysis - The main funds showed a net inflow in stocks like Su Yan Jingshen, while stocks like *ST Yatai experienced a significant net outflow from main funds [3] - Retail investors contributed positively to several stocks, indicating a mixed sentiment in the market [3]