上证基建指数报8015.85点，前十大权重包含三一重工等

Core Viewpoint - The Shanghai Infrastructure Index has shown a decline in performance over various time frames, indicating potential challenges in the infrastructure sector [1][2] Group 1: Index Performance - The Shanghai Infrastructure Index closed at 8015.85 points, with a decrease of 5.05% over the past month, 0.72% over the past three months, and 6.05% year-to-date [1] - The index reflects the overall performance of 50 listed companies in infrastructure-related fields on the Shanghai Stock Exchange, with a base date of December 31, 2004, set at 1000.0 points [1] Group 2: Index Composition - The top ten weighted companies in the index include China State Construction (9.94%), China Railway (9.54%), and China Electric Power Construction (8.11%) among others [1] - The index is composed entirely of companies listed on the Shanghai Stock Exchange, with infrastructure construction making up 53.61%, professional engineering 15.98%, housing construction 15.22%, and engineering machinery 15.19% [2] Group 3: Index Adjustment Mechanism - The index samples are adjusted biannually, with changes implemented on the next trading day following the second Friday of June and December [2] - Weight factors are generally fixed until the next scheduled adjustment, with provisions for temporary adjustments in special circumstances such as delisting or corporate restructuring [2]