There are many marketing units. A brokerage company can have many marketing units. The exchange adopts the mechanism of random+polling to read the order of each marketing unit, and rents independent marketing units or marketing units with fewer tenants, so the order has a greater chance of being read and executed earlier by the exchange. A securities company is a company that deals in securities or a securities company. It is a legal person enterprise specializing in securities trading, and it is an institution that specializes in securities business with the approval of the competent authorities and after the relevant administrative departments for industry and commerce have obtained the business license.