One hand is equal to one hundred shares, and the smallest trading unit of futures is one hand. Investors who have traded stocks know that stocks are at least bought and sold in one hand, and one hand is equal to one hundred shares. The same is true for futures. The minimum number of buyers and sellers for long and short positions, open positions and close positions are all one-handed. Because there are more than 40 varieties of futures, the corresponding trading unit of each variety is different, such as rebar 10 ton, 500 kg of eggs, silver 15 kg, coke 100 ton and so on.

Stocks refer to the number of stocks traded. In stock trading, "hand" is used as the trading unit of stock. In the regulations of Shenzhen Stock Exchange, Shanghai Stock Exchange and its Growth Enterprise Market, their marketing unit shares are all 100 shares and their integer multiples. Simply put, one hand is 100 shares. Only marketing unit in the Science and Technology Innovation Board is an exception, and its requirement is 200 shares and its integral multiple, that is, 200 shares in one hand. The Shanghai stock code starts with 60, the Shenzhen stock code starts with 00, the GEM stock code starts with 300, and the science and technology innovation board stock code starts with 688.

In any stock market, investors are allowed to buy stocks with one hand. Because the minimum amount of stock purchase is to start with one hand, it is feasible for investors to buy stocks greater than or equal to one hand. Although this is in compliance, we should know that it is easy for investors to increase transaction costs by buying stocks in one hand, and there are handling fees for stock trading. If they buy stocks in one hand, they have to charge subscription fees every time, which is not cost-effective from the perspective of capital efficiency.

Stock is a certificate of ownership issued by a joint-stock company, and it is a kind of valuable securities issued by a joint-stock company to all kinds of shareholders as a shareholding certificate to obtain dividends and bonuses. Each share represents the shareholder's ownership of the basic unit of the enterprise. Behind every stock is a listed company. At the same time, every listed company will issue shares. Every stock in the same category represents the equal ownership of the company. The share of ownership of the company owned by each shareholder depends on the proportion of shares held by each shareholder to the total share capital of the company. Shares are part of the capital of a joint-stock company and can be transferred, traded or mortgaged at a fixed price. It is the main long-term credit tool in the capital market, but the company cannot be required to return its capital contribution.