市场有效性研究与主、被动基金配置建议：中盘蓝筹风起，主动权益基金优势凸显

1. Report's Industry Investment Rating No industry investment rating information is provided in the report. 2. Core Viewpoints of the Report - The improvement of A-share market efficiency provides a solid foundation for the development of passive investment, with the scale of passive equity funds in the domestic public fund market exceeding 50% in 2025 [5]. - The effectiveness of the A-share market is lower than that of Hong Kong and US stocks, and the effectiveness of small-cap and technology stock indices is weaker than that of large-cap stock indices. The effectiveness of the A-share market shows an overall upward trend [5]. - There is a significant negative correlation between the excess return of active funds and index effectiveness. As the difficulty of obtaining Alpha increases, the demand for diversified Beta and Smart Beta on the equity side increases, highlighting the importance of asset allocation [5]. - There is a balance point between the scale ratios of active and passive funds. In the choice of funds, it is recommended to allocate ETFs in the large-cap style market, select active equity funds in the mid-cap style market, and choose quantitative funds for small-cap style allocation [5]. 3. Summary by Relevant Catalogs 3.1 A-share Equity Fund Market: Passive Investment Proportion Exceeds 50% - In 2025, the scale of domestic passive equity funds exceeded that of active equity funds for the first time, and this trend continues. The reasons include the difficulty of obtaining sustainable excess returns from active funds, the improvement of A-share market efficiency, and the development of domestic investment advisory services [9]. 3.2 Rise in Passive Investment Proportion Due to Market Efficiency Improvement - As market efficiency improves, it becomes more difficult to obtain Alpha, leading to the rise of Beta investment. Passive investment includes pure passive investment and factor-based passive investment (Smart Beta) [14]. - There is a balance point between active and passive funds, and the scale ratio of passive investment will not increase indefinitely. Ideal asset allocation should be an organic combination based on the market cycle, asset categories, and strategy capacity [15]. 3.3 Market Efficiency and Testing Methods 3.3.1 Origin and Connotation of the Efficient Market Theory - The study of market efficiency can be traced back to 1889, and Eugene Fama formally defined and improved the efficient market theory, dividing market efficiency into three levels: weak, semi-strong, and strong [18][19][20]. 3.3.2 Testing Methods for the Efficient Market Theory - Weak Form Tests: By testing whether the price sequence residual is white noise, it can be determined whether the stock price is likely to follow a random walk, which is used to judge market efficiency. The Ljung - Box test is commonly used for white noise testing [21][25][27]. - Semi - Strong Form Tests: Economists generally use the event study method to test the reaction speed of stock prices to public information [29]. - Strong Form Tests: This tests whether investors can obtain excess returns using insider information. It studies the returns of professional investors or insiders [30][31]. 3.4 Exploration of Market Efficiency in A-share, Hong Kong, and US Stocks - Since 2013, the efficiency of A-share has been slightly lower than that of Hong Kong and US stocks, and the efficiency of small-cap and technology stock indices is weaker than that of large-cap stock indices. After 2018, the efficiency of the A-share market has increased rapidly [34][38][40]. - There is a significant negative correlation between the excess return of active funds and index efficiency. As market efficiency improves, the difficulty of obtaining Alpha in A-shares increases [43]. 3.5 Fund Investment Choices under the Background of Improved Market Efficiency 3.5.1 ETF: Emphasizing Multi-Asset ETFs and Equity Smart Beta - As the demand for diversified Beta increases, the importance of asset allocation becomes prominent. ETFs are becoming increasingly important in the strategic position of asset allocation, and the proportion of ETFs in the holdings of public FOFs continues to rise, with diversified demand [47][50]. - Strategy ETFs (Smart Beta factor ETFs) show relatively independent trends, providing a source of differentiated Beta in the equity market and playing an important role in asset allocation [52]. - Industry ETFs are mostly market - capitalization weighted, with large-cap stocks contributing more to returns. Since it is difficult to obtain excess returns from large-cap stocks, investment is recommended to be based on long - term allocation [55][56]. 3.5.2 Active Equity and Quantitative Investment: Obtaining Alpha Returns from Small and Mid - Cap Stocks - Active equity funds are more exposed to mid - cap stocks. The trading environment of mid - cap stocks is more friendly to actively managed funds, with lower pricing efficiency and lower difficulty in obtaining excess returns compared to large - cap stocks, and relatively sufficient liquidity [61][62]. - Quantitative funds may be a better choice for investing in small - cap stocks. Quantitative strategies can improve the objectivity and winning rate of decision - making, and have advantages in terms of stock coverage and trading execution [69][70][71].