Abstract: Under the registration system, the issuance of new shares adopts a review and inquiry system with information disclosure as the core, aiming to improve regulatory transparency and reduce the degree of information asymmetry in the review of new share issuance. Taking the companies successfully listed on the Science and Technology Innovation Board from July 2019 to December 31, 2023 as the research object, this study analyzes the impact and mechanism of review inquiries on IPO underpricing rate from the perspectives of the exchange review inquiry intensity, the issuing company’s response intensity to review inquiry letters, the exchange review inquiry attitude, and the issuing company’s response attitude to review inquiry letters. Research has shown that the intensity of exchange review inquiries, the strength of issuing companies’ responses to review inquiry letters, the attitude of exchange review inquiries, and the attitude of issuing companies towards review inquiry letters have reduced the IPO underpricing rate. The mechanism research has found that the intensity of exchange review inquiries, the strength of issuing companies’ responses to review inquiry letters, the attitude of exchange review inquiries, and the attitude of issuing companies towards review inquiry letters can promote risk information disclosure by companies, thus review inquiries can reduce IPO underpricing rates. Further research has found that the effect of review inquiries on reducing IPO underpricing is mainly reflected in reducing the primary market discount rate. In the medium to long term, the stronger the intensity of exchange review inquiries and the more negative the attitude, the lower the medium to long-term holding yield for investors and the higher the efficiency of stock price pricing. To this end, issuing companies should actively disclose information, regulatory agencies should pay attention to the impact of the number of questions, topic distribution, and text sentiment in inquiry letters on IPO inhibition rates, and investors should deeply analyze the exchange’s inquiry letters and the issuing companies’ responses to the inquiry letters.

Key words: registration system, review inquiry letter, IPO discount rate, text analysis