It refers to a fund operation mode that fund promoters can sell fund shares or shares to investors at any time according to their needs when setting up a fund, and can redeem the issued fund shares or shares at the request of investors. Investors can buy funds through fund sales agencies, so that the assets and scale of the fund will increase accordingly, or they can sell their fund shares to the fund to recover cash, so that the assets and scale of the fund will decrease accordingly.

According to whether it can be listed on the stock exchange, open-end funds can be divided into listed open-end funds and contractual open-end funds.

According to different investment objects, open-end funds can be divided into stock funds, bond funds, mixed funds, money market funds, futures funds, option funds and warrant funds.

According to different investment objectives, open-end funds can be divided into growth funds, income-oriented funds and balanced funds.