1, tracking error, index funds generally choose smaller tracking error, the smaller the tracking error, the closer to the index;

2. The setting of heavyweights, the index fund does not completely copy the index, and the setting of heavyweights and the selection of constituent stocks will make the fund and index very different;

3. large redemption. The impact of large subscription on index funds is mainly to dilute the rise and fall of fund net value the next day. Large redemption will have a certain impact on index funds.