沪指涨超1%重回4000点，脑机接口概念集体爆发

Market Overview - The market opened higher on January 5, with the Shanghai Composite Index returning to the 4000-point level for the first time in 34 trading days, and the ChiNext Index rising over 2% [1] - By the midday close, the Shanghai Composite Index increased by 1.07%, the Shenzhen Component Index rose by 1.87%, and the ChiNext Index gained 2.15% [1] - The total trading volume in the Shanghai and Shenzhen markets reached 1.64 trillion yuan, an increase of 323.8 billion yuan compared to the previous trading day [1] Index Performance - Shanghai Composite Index: 4011.45, up 1.07% [2] - Shenzhen Component Index: 13777.32, up 1.87% [2] - ChiNext Index: 3272.07, up 2.15% [2] - North Star 50 Index: 1459.32, up 1.31% [2] Sector Highlights - Over 4000 stocks in the market experienced gains, with 98 stocks hitting the daily limit [2] - The brain-computer interface sector saw significant activity, with over twenty constituent stocks hitting the daily limit, including Sanbo Brain Science, Meihao Medical, and Innovation Medical [2] - The commercial aerospace sector remained active, with China Satellite Communications achieving three consecutive trading limits in five days [2] - The insurance sector strengthened, with Xinhua Insurance and China Pacific Insurance both reaching historical highs [2] - The semiconductor industry chain showed robust performance, with stocks like Yaxiang Integration and Shenghui Integration hitting the daily limit [2] - Conversely, the Hainan Free Trade Zone concept stocks collectively declined, with Hainan Development hitting the daily limit down [2]