The net value of fund units is the net asset value of each fund unit, which is equal to the balance of the total assets of the fund minus the total liabilities divided by the total number of units issued by the fund. The subscription and redemption of open-ended funds are carried out at this price. The transaction price of closed-end funds is the market price that has been confirmed at the time of transaction; In contrast, the unit transaction price of open-ended funds depends on the net asset value of unit funds that are not known at the time of subscription and redemption (but can be calculated after the market closes on the day and announced on the next trading day).

Stocks are now nearly 400 years old. The earliest stock market arose in 1602 when the Dutch and British established overseas trading companies. These companies are established by raising share capital and have obvious characteristics of joint-stock companies; they have legal person status; a board of directors is established; the general meeting of shareholders is the company's highest authority; dividends are distributed according to shares; and a limited liability system is implemented. The successful operation and rapid development of the joint-stock company made more enterprises follow suit.