Core Viewpoint - The article discusses the calendar effect observed in the A-share market, where certain market styles exhibit better performance in specific months, suggesting the presence of seasonal factors influencing these patterns [2][4]. Summary by Sections Calendar Effect of Styles - The small-cap style shows significant volatility in the first half of the year, with better performance in the second half. Specifically, April has weak performance for small-cap stocks, while March and May yield higher average returns [4][13]. - The growth style demonstrates a "high early, low late" pattern, with notable excess returns in January and June-July, achieving a win rate of 90.9% [4][13]. - The quality style exhibits strong performance in both January (excess return of 1.4%, win rate of 81.8%) and December (excess return of 0.5%, win rate of 80%) [4][14]. - The dividend style performs well in April and August, with a win rate of 83.3%, but shows lower performance in June and October [4][15]. Mechanisms Behind Calendar Effects - The performance of growth and small-cap styles is significantly influenced by the rhythm of financial report disclosures, with concentrated disclosures in January, April, and July favoring growth stocks [5][20]. - High dividend announcement days and ex-dividend days can impact the performance of dividend stocks, with positive excess returns following high dividend announcements and negative returns post ex-dividend days [5][24]. - Institutional investors exhibit seasonal changes in risk preferences, with a tendency to favor growth stocks mid-year and quality stocks towards year-end, impacting the performance of respective styles [5][35]. Implications for Investment Strategy - Investors are advised to focus on growth opportunities during the earnings announcement periods in January and April while avoiding small-cap stocks during these times [23][35]. - Attention should be given to the concentration of dividend announcements in March and April, which can enhance the performance of dividend styles, while caution is warranted during the ex-dividend periods [30][34].