To put it simply, an underwriter is a service provider who helps the client underwrite products, but does not produce products itself. Underwriters in the financial market are usually defined for securities, and stocks are the most important content in securities underwriting. In fact, the securities industry has relevant regulations. When securities are listed for trading, issuers often need to find underwriters to underwrite securities, and it is common for securities firms to play the role of underwriters. Of course, in addition to securities firms, sometimes banks and other financial institutions will also play the role of underwriters. Some larger companies, such as Alibaba and Tencent, may have underwriting groups to jointly provide underwriting services for the company's issuance of securities when they go public.