Viewpoint: Index funds are products of fund companies. The products sold by fund companies are funds, and fund products are designed through models. Model design is the product of fund managers and fund researchers, and managers are also fund managers. At the beginning of the design, there will be investment targets, such as E Fund's Shanghai and Shenzhen 300ET. The investment target is the stocks in the Shanghai and Shenzhen 300, and the stocks outside this 300 cannot be invested.

The design of fund products includes contract elements such as setting, dividend cycle, management fee and liquidation line.