A股收评：三大指数集体下跌，沪指4000点得而复失，北证50指数跌1.2%，船舶制造、福建板块领涨！2900股下跌成交2.17万亿缩量1913亿

Core Viewpoint - The A-share market experienced fluctuations, with major indices initially rising but later declining, resulting in the Shanghai Composite Index falling below 4000 points again [1]. Market Performance - The Shanghai Composite Index closed at 3988.22, down 0.22% [2]. - The Shenzhen Component Index decreased by 0.44%, closing at 13430.10 [2]. - The ChiNext Index fell by 0.15%, ending at 3229.58 [2]. - The North China 50 Index dropped by 1.2%, closing at 1451.57 [2]. - Total market turnover was 2.17 trillion yuan, a decrease of 191.3 billion yuan from the previous trading day, with over 2900 stocks declining [1]. Sector Performance - The shipbuilding sector saw gains, with Jianglong Shipbuilding (300589) hitting the daily limit [3]. - The Fujian sector surged following a favorable article on cross-strait relations, with multiple stocks like Helitai (002217) and Haixia Innovation reaching their daily limits [3]. - The shipping and port sector also performed well, with Haitong Development hitting the daily limit [3]. - Other sectors with notable gains included superconducting concepts, automotive services, fluorochemical, and PCB [3]. - Conversely, the gold and precious metals sector declined, with Chifeng Gold (600988) leading the drop [3]. - The wind power equipment sector fell, with Daikin Heavy Industries (002487) dropping over 8% [3]. - The cultivated diamond sector weakened, with Huifeng Diamond declining nearly 6% [3]. - Other sectors with significant declines included non-ferrous metals, beauty care, steel, and combustible ice [3].