Core Viewpoint - The article discusses the periodic adjustments of sample stocks in major A-share indices, emphasizing the importance of these adjustments in reflecting market trends and economic development [3][5]. Group 1: Index Adjustment Mechanism - The adjustment of indices can be categorized into periodic and temporary adjustments, with periodic adjustments typically occurring semi-annually in June and December [5]. - The recent adjustments affected multiple core indices, including the Shanghai Stock Exchange 50, 180, 380, and others, with changes implemented on December 12 and 15, 2025 [3][6]. - The adjustments aim to ensure indices accurately reflect market conditions and to eliminate underperforming stocks, thereby maintaining the indices' integrity [5][6]. Group 2: Sample Stock Changes - The adjustments involved significant changes in sample stocks across various indices, with the Shanghai Stock Exchange 50 changing 4 stocks, the Shanghai and Shenzhen 300 changing 11 stocks, and the CSI 500 changing 50 stocks [6][8]. - The adjustments also included the addition of companies with strong performance and growth potential, particularly in sectors like information technology and high-end manufacturing [6][12]. Group 3: Industry Structure Optimization - The recent adjustments have led to an optimization of the industry structure within the indices, increasing the representation of new quality productivity sectors such as information technology and renewable energy [12]. - For instance, the Shenzhen Component Index saw a shift with 10 companies removed and 10 new companies added, enhancing its focus on innovative sectors [12][13]. Group 4: Financial Performance and Investor Returns - The adjusted indices show strong financial performance, with the Shenzhen Component Index's manufacturing companies representing 76% of its sample, and over 30% being industry leaders [12][14]. - The new sample companies in the indices have demonstrated significant growth, with the Shenzhen Component Index's companies reporting a 16% increase in revenue and a 24% increase in net profit year-on-year [12][14]. Group 5: Market Reactions to Adjustments - The article notes that adjustments to index components can influence stock prices, with stocks added to indices often experiencing price increases prior to the adjustment date [16][17]. - Historical data suggests that stocks added to indices tend to achieve excess returns, although the impact may be limited due to pre-adjustment speculation by investors [17].

年末的此轮指数样本调整，几乎囊括了A股市场的大部分核心指数。 11月末，沪深交易所、中证指数有限公司（下称"中证指数"）、深圳证券信息有限公司（下称"深证信息"）等集中公告， 根据指数规则，对A股多个核心指数进行样本股定期调整。 此轮调整，几乎囊括了A股市场的核心指数，具体包括上证50、上证180、上证380、科创50、沪深300、中证500、中证 1000、中证A50、中证A100、中证A500以及深证成指、创业板指、深证100、创业板50等。 其中，上交所与中证指数的调整已于2025年12月12日收市后生效，而深交所及深证信息的调整则于12月15日正式实施。 业内人士认为，A股指数的定期调整机制，是保持指数生命力的重要举措，其核心是为了让指数能够更精准地反映市场趋 势和经济发展方向。 指数们的"新陈代谢" 据了解，指数调样分为定期调整和临时调整，其中，定期调整的周期包括季度、半年度、年度等三类。其中，最常见的是 半年度调整，一般在每年的6月和12月进行，生效日通常是6月、12月第二个星期五的下一交易日。 部分科技创新领域的指数，由于行业更新换代较快，所以采用季度调整的形式。如科创50指数样本年内分别于3月 ...

Group 1: Optical Modules - The optical module industry is experiencing the highest growth and performance realization among AI hardware this year, driven by high verification barriers for North American CSP tech giants and increasing demand due to the acceleration of supernode technology [2][4] - The average ratio of optical modules to GPUs is continuously increasing, with demand for 800G and 1.6T optical modules being revised upwards, indicating a strong upward resonance in demand [2][4] - By 2026, the demand for 1.6T optical modules is expected to exceed 30 million units, with an average price of $900-1000 per unit, while high-end EML optical chips are projected to face a 25-30% supply shortage [4][5] Group 2: Liquid Cooling - The liquid cooling industry has seen fluctuating trends this year, with initial enthusiasm dampened by low penetration rates, followed by a resurgence in August and significant breakthroughs in November [5][9] - The demand for liquid cooling in North America is expected to expand rapidly by 2026, with penetration rates in the NVIDIA ecosystem projected to rise from 20-30% to over 80-90% [7][9] - A leading domestic manufacturer is anticipated to capture a market share of 13-17% in North America by 2026, with Google expected to implement liquid cooling solutions for over 200,000 TPU V7 chips, creating a market space exceeding $24-28 billion [9][10] Group 3: AI PCB - The AI PCB industry is thriving, with companies like Shenghong, Huidian, and Shengyi achieving performance realization in North America, despite some quarterly fluctuations [10][12] - The supply side is seeing an increase in product value and manufacturing difficulty due to upgrades in customer chips and cabinet solutions, leading to a marginal differentiation in the supply landscape [10][12] - By 2026, the introduction of orthogonal backplanes is expected to significantly increase unit value, with M9 material processing anticipated to break through, although mass production is expected to ramp up in 2027 [12][13] Group 4: Server Power Supply - The server power supply market has shown similar trends to liquid cooling, with initial excitement followed by a divergence in performance among manufacturers [13][14] - The supply side is dominated by Taiwanese manufacturers, with a high concentration of market share, while domestic manufacturers are expected to make significant breakthroughs in North America by 2026 [14][15] - The adoption of HVDC technology is projected to replace traditional UPS solutions, with an expected market scale exceeding $20-30 billion by 2026 [15]