Zheng Xing Xing Ye Ri Bao·2025-09-18 08:59Group 1 - The oil service engineering sector experienced a decline of 1.65% on September 18, with Tongyuan Petroleum 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] - Major stocks in the oil service engineering sector showed significant declines, with Tongyuan Petroleum down 5.90% and Zhun Oil Co. down 4.65% [1] Group 2 - The net outflow of main funds in the oil service engineering sector was 258 million yuan, while retail investors saw a net inflow of 220 million yuan [1] - The table of fund flows indicates that several companies, including Huibo Yin and Zhongyou Engineering, experienced varying levels of net inflow and outflow from different investor types [2] - Notably, potential investment opportunities may arise from the contrasting behaviors of retail and institutional investors in this sector [2]