市场探底回升，沪指微跌0.07%险守4000点，医药等防御性板块逆势走强

Market Overview - The market showed signs of recovery after hitting a low, with the Shanghai Composite Index slightly down by 0.07% and the ChiNext Index briefly turning positive at the close [1] - The total trading volume in the Shanghai and Shenzhen markets was 1.95 trillion, a decrease of 486 billion compared to the previous trading day [5] Index Performance - Shanghai Composite Index closed at 4000.14, down 0.07% with 716 gainers and 1553 losers [2] - Shenzhen Component Index closed at 13240.62, down 0.36% with 934 gainers and 1901 losers [2] - ChiNext Index closed at 3122.03, down 0.39% with 448 gainers and 923 losers [2] Sector Performance - Defensive sectors showed strength, with oil and gas concepts surging, leading to stocks like PetroChina and Zhenhua Oil hitting the daily limit [2] - The pharmaceutical sector continued to rise, particularly in cell immunotherapy, with stocks like Kaineng Health and Jimin Health also hitting the daily limit [2] - The banking sector performed strongly, with Agricultural Bank of China and Industrial and Commercial Bank of China reaching historical highs [2] - Consumer stocks were active, with companies like Sanyuan and Zhongrui achieving consecutive gains [2] - The lithium battery sector saw a late rally, with Tianji shares performing well [2] - In contrast, superhard material stocks experienced significant declines, with World falling over 10% [2][3] Market Sentiment - Overall, more than 3500 stocks in the market declined, indicating a broad-based sell-off [2] - The market had a high limit-up rate of 75%, with 58 stocks hitting the limit and 19 stocks touching the limit-down [6]