A股走势分化，沪指回落走低，英伟达概念爆发

Market Overview - A-shares exhibited a mixed performance on July 15, with the Shanghai Composite Index falling approximately 1% at one point, dropping below 3500 points, while the ChiNext Index surged over 2% [1] - The Shanghai Composite Index closed down 0.42% at 3505 points, the Shenzhen Component Index rose 0.56% to 10744.56 points, and the ChiNext Index increased by 1.73% to 2235.05 points [1] - The total trading volume in the Shanghai and Shenzhen markets reached 16.353 billion yuan, an increase of over 1.5 billion yuan compared to the previous day [1] Sector Performance - The power and coal sectors experienced declines, with companies like Huayin Power and Tuori New Energy hitting the daily limit down, and Dayou Energy dropping over 9% [1] - The banking sector also saw losses, with Qilu Bank falling over 3% and Ping An Bank and Zheshang Bank declining around 2% [1] - Conversely, AI-related stocks performed well, with significant gains in CPO concept stocks, including a 20% increase for Xinyisheng, which reached a historical high [1][3] AI Sector Developments - Nvidia's announcement to resume sales of the H20 GPU in China and the introduction of a new compliant GPU is expected to alleviate the domestic chip shortage in computing power [4][5] - The H20 chip's return is anticipated to meet some of the demand for training and inference of domestic AI models, potentially enhancing the hardware and software capabilities of domestic AI models [5] - The AI agent concept is gaining traction, with stocks like Dingjie Zhizhi and Chutian Long hitting the daily limit up, reflecting strong market interest [10] Power Sector Decline - The power sector saw a collective retreat, with notable declines in stocks such as Huayin Power and Tuori New Energy, both hitting the daily limit down [9] - Huayin Power's stock had previously surged over 100% in the last ten trading days, raising concerns about potential short-term price corrections [11] - Tuori New Energy projected a loss of 48 million to 68 million yuan for the first half of the year due to intensified competition in the photovoltaic industry and supply-demand imbalances [12]