Indices can't be bought separately, only index funds can be bought, and index funds are a kind of funds. It tracks a specific index and buys some or all of the stocks in the index in order to obtain the same income as the index.

Index funds have both on-site funds and off-site funds. OTC funds are purchased on sales platforms (Tian Tian Fund, Alipay, WeChat, banks and brokers). On-site funds need to open an on-site fund account to be traded (brokers open an account). In recent years, index funds have attracted more and more attention from investors because of their relatively small risks and high returns.