沪指重回4000点，脑机接口近20股涨停，存储芯片大爆发，千亿锂矿巨头创3年半新高

Market Overview - The A-share market opened higher on January 5, with the Shanghai Composite Index surpassing 4000 points for the first time in 34 trading days, reaching 4007.66 points, up by 38.82 points or 0.98% [1][2]. Brain-Computer Interface Sector - The brain-computer interface concept saw a surge, with stocks like Meihua Medical and Aipeng Medical hitting the daily limit, while nearly 20 stocks including Beiyikang and Sanbo Neuroscience also reached their limits. Other stocks like Guanhao Biological and Hanwei Technology rose over 10% [3][4]. Lithium Mining Sector - The lithium mining sector experienced fluctuations, with Salt Lake Holdings hitting the daily limit and reaching a three-and-a-half-year high. The company projected a net profit of 8.29 billion to 8.89 billion yuan for 2025, representing a year-on-year growth of 77.78% to 90.65% [5][6]. Storage Chip Sector - The storage chip sector strengthened, with stocks like Jiangbolong rising over 14% and Shanghai Xinyang over 12%. The demand for storage chips is expected to surge due to strong AI demand, with significant price increases projected for DDR4 and DDR5 memory chips [7][9]. AI Infrastructure Investment - Major North American cloud service providers, including Google, Meta, Microsoft, and Amazon AWS, are expected to invest a record $600 billion in AI infrastructure by 2026. This demand is anticipated to drive up storage chip prices significantly, with DDR4 and DDR5 memory prices expected to rise by 1800% and 500%, respectively [9].