ETF-linked funds refer to funds that invest most of their assets in tracking the same underlying index, that is, invest in ETF funds (referred to as target ETFs), closely track the performance of the underlying index, pursue the minimization of tracking deviation and tracking error, and adopt an open operation mode.

Trading open index securities investment fund, referred to as ETF, manages stock portfolio. The types of stocks in this portfolio are the same as those in a specific index, such as the SSE 50 Index, and the number of each stock is consistent with the proportion of the constituent stocks of this index. The transaction price of ETF depends on the value of its stock portfolio, that is, the "net asset value of unit fund". ETF's portfolio usually completely replicates the underlying index, and its net performance is highly consistent with the specific index pegged. For example, the net performance of SSE 50ETF is highly consistent with the rise and fall of SSE 50 index.