ETF-linked fund is a fund that invests most fund assets in an ETF (called target ETF), closely tracks the performance of the underlying index, and can be purchased and redeemed off-site (bank channels, etc.). ). The main characteristics of ETF linked funds are: (1) Linked funds are attached to the main fund. Through the main fund investment, if the main fund does not exist, the linked fund does not exist. Therefore, the linked fund and ETF are two different parts of the same legal entity, and the linked fund is in a subordinate position. (2) Linked funds provide channels for banks, securities companies and Internet company platforms to purchase ETFs, which can attract a large number of bank and Internet company platform customers to directly participate in ETF investment through linked funds and enhance the influence of ETFs. Linked funds mainly open the way for small and medium investors of banks and Internet companies to buy ETFs. (3) Linked funds can intervene in the operation of ETFs by providing regular fixed investment that ETFs do not currently have. (4) Linked funds cannot participate in ETF arbitrage, and the main purpose of developing linked funds is to enlarge the scale of index funds. The purpose of connecting funds is not arbitrage, but to introduce funds through off-exchange channels, expand the scale of index funds and promote indexed investment. (5) The linked fund is a fund within a fund (FOF), and the market value of the target ETF held by the ETF linked fund shall not be less than 90% of the net asset value of the linked fund.