Open-end fund. Open-end fund investors can purchase and redeem at will, except for large redemption. Ordinary purchase and redemption will not affect the normal operation of the fund, and the fund scale will change with the purchase and redemption of investors. Fund size refers to the total assets of the fund. When choosing a fund, investors should avoid it if it is too big or too small. The size of the fund is preferably between 2 billion and 8 billion.