Closed-end fund is a special kind of investment fund, which is different from open-end fund, mainly in the scale of fund share and trading mode.

Closed-end funds have the following characteristics:

1. fixed share: a fixed issuance scale will be set when a closed-end fund is established, and it will remain unchanged after the fund is established. Investors can only participate in investment by buying and selling fund shares, and cannot purchase or redeem fund shares at any time.

2. Trading method: After the establishment of closed-end funds, they are usually listed and traded on the stock exchange, and investors can buy and sell fund shares in the secondary market through securities accounts. Therefore, the transaction price of closed-end funds will be affected by the relationship between market supply and demand, which may be higher or lower than the fund's net asset value (NAV).

3. Duration: Closed-end funds usually have a fixed duration, generally 5 years, 10 years or longer. During its existence, the fund share remains unchanged, and investors can only buy and sell the fund share through the secondary market. At the end of the duration, the Fund can choose to postpone, liquidate or convert into an open-end fund.

4. Investment strategy: Closed-end funds are similar to open-end funds in investment strategy, and can invest in assets such as stocks, bonds and money market instruments. However, due to the fixed share of closed-end funds, fund managers may be more flexible in investment operations, without considering the pressure of redemption.

Compared with open-end funds, closed-end funds have the following advantages:

1. Efficiency of capital utilization: As the share of closed-end funds is fixed, fund managers can make more effective use of funds for long-term investment and improve the return on investment.

2. Trading method: investors can buy and sell closed-end funds through the stock exchange, which is more convenient and more liquid.

3. Discount or premium: The transaction price of closed-end funds may be lower or higher than the fund's net asset value, providing investors with more investment opportunities.

It should be noted that closed-end funds still have certain risks when investing, and investors need to choose appropriate fund products according to their risk tolerance and investment objectives.