Securities underwriting refers to a series of activities conducted by securities companies with the qualification for securities underwriting business, where they accept the entrustment of securities issuers to sell the proposed securities within the legally prescribed or agreed time frame, utilizing their own good reputation and sales channels, and thereby collect a certain percentage of underwriting fees. According to legal provisions, underwriting is divided into consignment and exclusive sales, which are distinguished based on the different forms of underwriting responsibility. The key difference between consignment and exclusive sales lies in the nature of the relationship: the former is merely a general principal-agent relationship. If the sales target for the securities cannot be achieved within the statutory or agreed period, the remaining securities are returned to the issuing company, and the securities company does not bear the issuance risk, resulting in lower fees. In contrast, exclusive sales refer to full underwriting, where if the securities company fails to sell all the issued securities within the relevant time frame, it must purchase the entire remaining balance. This exposes the securities company to greater risk and thus commands higher fees, often requiring financing to meet the capital demand for the remaining balance of exclusive sales.