主动量化周报：元旦特别篇：小微盘的复苏-20260104

• The report discusses the impact of ETF scale disturbances on the A500 index, which has led to an early pricing of post-holiday positive expectations. This has limited the marginal tightening space for quantitative strategy risk exposure, with the recovery of micro-cap stocks expected to occur earlier than usual in January 2026[1][11] - The IM basis dimension is highlighted as a key factor, with the annualized IM basis fluctuating significantly between 18% and 5% by the end of December 2025, eventually converging to around 5%. This basis change is expected to catalyze the recovery of micro-cap stocks as hedging strategies rebuild positions after the holiday[2][12] - The report emphasizes the long-term bull market of micro-cap stocks in the A-share market, driven by two main factors: the relatively low delisting probability in the A-share market compared to the U.S. market, which increases shell value, and the higher proportion of individual investors in the A-share market, who prefer small-cap stocks, providing them with higher liquidity[3][13] - Historical data over the past decade shows that micro-cap stocks have achieved a cumulative return of 552%, significantly outperforming most other investment categories. The report notes that micro-cap stocks tend to perform well in the absence of a clear market mainline, benefiting from liquidity premiums during periods of market volatility[3][13] - The report predicts a post-holiday market rotation, with large-cap stocks leading initially, followed by small-cap stocks. The A500 index's valuation uplift is expected to create upward space for micro-cap stocks, with liquidity spillover effects likely to emerge in mid-to-late January 2026, driving a new round of micro-cap stock rallies[4][14]