If the index fund is in a closed period, it is impossible to make a fixed investment, and the ETF fund belongs to the index fund. ETF funds are traded on stock exchanges, so it is generally impossible to set a fixed investment (some securities companies can set a condition sheet to achieve the purpose of fixed investment in disguise).

Index fund is a kind of fund, which takes a specific index as the tracking object and buys some indexes to obtain all the constituent stocks in order to obtain the same income as the index.