沪指失守4000点，投资者应关注哪些板块？

Market Overview - The A-share market experienced a significant decline, with major sectors such as telecommunications, electronics, and defense leading the drop, while steel and non-ferrous metals provided some support [1][2] - The Shanghai Composite Index closed down 0.73% at 3986.9 points, and the ChiNext Index fell 1.84% to 3263.02 points, indicating a broad market downturn [2] - Trading volume increased to 2.46 trillion yuan, up from 2.29 trillion yuan the previous day, indicating heightened market activity despite the decline [2] Sector Performance - High-profile sectors such as AI, semiconductor, and communication devices saw significant pullbacks, while rare earths, steel, and coal sectors showed resilience [4][5] - Specific stocks like "Yizhongtian" in the CPO concept faced substantial declines, with New Yisheng down 7.9% and Tianfu Communication down 11.56% [5][6] Investment Sentiment - Analysts suggest that the downward space for indices is limited, with expectations of fluctuations around the 4000-point mark, indicating a potential for a "high-low switch" market [1][10] - The market is expected to see structural upward trends, driven by a combination of macroeconomic recovery and positive policy signals from the US-China trade talks [11][14] Key Investment Opportunities - Focus on sectors with lower previous gains but higher future earnings certainty, such as humanoid robot components and smart automotive sectors, particularly those closely linked with Tesla [13] - Continued interest in AI, photovoltaic sectors, and lithium batteries, with a cautionary note on avoiding stocks with disappointing third-quarter results [14] - The semiconductor industry remains a long-term investment focus, particularly in storage chips currently in a price increase cycle [14]