If you don't want to make a fixed investment, you can make a closed-end fund fixed investment on the total assets page.

Whether fund units can be increased or redeemed can be divided into open-end funds and closed-end funds. Open-end funds are not traded on the market, but are purchased and redeemed through banks, brokers and fund companies. The fund scale is not fixed, and closed-end funds have a fixed duration. Generally listed on the stock exchange, investors buy and sell fund shares through the secondary market.