Group 1 - The core index of the China Securities Intelligent Selection Shipbuilding Industry Index decreased by 1.11%, closing at 1364.1 points with a trading volume of 15.999 billion [1] - Over the past month, the index has increased by 8.15%, 17.14% over the past three months, and 7.60% year-to-date [1] - The index includes 40 representative listed companies involved in ship materials, ship supporting, ship manufacturing, and shipping, reflecting the overall performance of the shipbuilding industry [1] Group 2 - The top ten weighted companies in the index are China Shipbuilding (14.81%), China Power (14.66%), China Heavy Industry (14.4%), China Ship Technology (6.66%), China Ship Defense (6.3%), Tianhai Defense (5.5%), China Marine Defense (5.42%), Zhenhua Heavy Industry (5.21%), Yaxing Anchor Chain (3.85%), and Weichai Heavy Machinery (3.39%) [1] - The index's holdings are primarily listed on the Shanghai Stock Exchange (81.63%) and the Shenzhen Stock Exchange (18.37%) [1] - The industry composition of the index holdings shows that industrial companies account for 93.98%, raw materials for 3.78%, and information technology for 2.24% [1] Group 3 - The index sample is adjusted every six months, with adjustments occurring on the next trading day after the second Friday of June and December [2] - The number of samples adjusted at each time generally does not exceed 20% [2] - Weight factors are adjusted along with sample changes, and special circumstances may lead to temporary adjustments [2]