The article looks at how different factors affect the performance of index investments in China. It examines fund managers and companies, and how their characteristics impact investment performance. The study finds that fund tracking errors are influenced by institutional holdings and the stock selection ability of fund managers. Female fund managers tend to have smaller tracking errors. Institutional investors help improve active investment performance. Fund managers' stock selection ability reduces sensitivity to index fluctuations, while timing ability improves fund allocation performance. Overall, funds managed by female fund managers are less affected by index fluctuations.