市场环境因子跟踪周报（2025.12.12）：A股调整稳固，商品趋势度提升-20251218

• The report covers the period from December 8, 2025, to December 12, 2025[2][10] - The A-share market showed limited incremental funds and a characteristic of stock game due to seasonal tightening of funds towards the end of the year[3][10] - In the stock market, the style was biased towards small-cap and growth, with decreased volatility in the small-cap style and increased volatility in the growth style[11][13] - The market structure showed a decrease in industry excess return dispersion, industry rotation speed, and the proportion of rising constituent stocks[11][13] - The trading concentration increased for the top 100 stocks but decreased for the top 5 industries[11][13] - Market activity showed a decline in both market volatility and turnover rate[12][13] - In the commodity market, trend strength increased, especially in precious metals and non-ferrous metals, while the basis momentum rose in the energy and chemical sectors but fell in others[26][33] - Volatility increased in all sectors except energy and chemicals, with precious metals maintaining high volatility, and liquidity rose slightly in all sectors except black metals[26][33] - In the options market, the implied volatility of the SSE 50 and CSI 1000 further declined to historical lows, with the put skew decreasing for the SSE 50 and increasing for the CSI 1000[37] - In the convertible bond market, the market showed low volatility, with the premium rate of bonds convertible at par remaining high, the pure bond premium rate decreasing, and the proportion of low premium convertible bonds declining[41]