北证50日内跌幅达1.05%，铜冠矿建跌7.73%

Group 1 - The North Exchange 50 index has experienced a decline of 1.05% over the past 50 days [1] - Among the constituent stocks, Tongguan Mining Construction has dropped by 7.73% [1] - Liancheng CNC has decreased by 4.06% [1] - Xingtong Measurement and Control has fallen by 3.73% [1] - Weida Optoelectronics has seen a decline of 2.94% [1]