ETF redemption transaction means that investors can purchase and redeem ETF shares in the primary market at any time with portfolio securities, cash or other consideration agreed in the fund contract within the time stipulated in the contract. ETF fund is a kind of index fund, which is called transactional open-end fund. ETF funds generally adopt a passive strategy to track the market index of a certain target. Compared with ordinary index funds, ETF funds have the advantages of high transparency, low management cost and greater flexibility.