This study focuses on “how long” the hot markets continue for a specific IPO firm in the secondary market after listing, which is defined as “honeymoon” or “honeymoon period”, more specifically, as the number of days from the date of listing to the date with the highest price within a month after listing. Our findings are as follows: First, honeymoon periods exist on the Shanghai Stock Exchange and Shenzhen Stock Exchange, with rising stock prices for some days after IPO. Second, the honeymoon period has a positive (+) effect on the long-term market performance of IPO firms. We find that a firm with a longer IPO honeymoon period also has a higher long-term abnormal return with both CARs and BHARs used in regression models for all periods (one year, three years, and five years). Third, lock-up contracts have a positive (+) effect on IPO firms’ initial returns. Fourth, lock-up contracts have a negative (-) effect on the honeymoon period. There is no evidence that lock-up contracts prolong the honeymoon period. Fifth, lock-up contracts have a positive (+) effect on the long-term abnormal returns for one year after the IPO. However, we find that firms with higher stock lock-up ratios have worse returns in three-year and five-year abnormal returns.

Keyword：Honeymoon, Lock-up period, IPO, Information asymmetry, China, Stock Returns​