Core Logic and Regulatory Basis - The lock-up period is not unique to NASDAQ but is based on regulations from the SEC (such as Rule 144 and Rule 145) and NASDAQ's listing rules (like Listing Rule 5635) [2][3] - The primary purpose is to stabilize stock prices, prevent short-term selling pressure, and protect investor confidence by restricting resale of shares by certain parties [2] Main Applicable Entities and Lock-Up Duration - Affiliates (company insiders) face a 180-day lock-up period starting from the first day of trading, which is the strictest requirement [3][4] - Non-affiliate early investors have a 6-month holding period plus restrictions under Rule 144 [5][8] - Underwriters (investment banks involved in the IPO) have a 30-day lock-up period from the first day of trading, which is the shortest [9][11] Special Circumstances - SPAC sponsors typically have a lock-up period of 12-24 months, while shares released to public shareholders from the trust account have no lock-up period [12][13] - In direct listings, there is no underwriter lock-up period, but company insiders still adhere to the 180-day lock-up rule [12][13] Post-Lock-Up Resale Restrictions - Even after the lock-up period ends, both affiliates and non-affiliates must comply with SEC Rule 144, which includes a 6-month holding requirement and resale limitations [12] Consequences of Violating Lock-Up Period - NASDAQ may impose penalties such as trading suspension, public reprimand, or delisting for violations [12] - Legal liabilities may arise if violations lead to investor losses, potentially resulting in civil lawsuits [12] - A record of violations can damage the market reputation of the company and its insiders [12] Summary of Key Conclusions - Affiliates face a 180-day lock-up period, the strictest requirement [12] - Non-affiliate early investors must meet a 6-month holding period plus resale restrictions [12] - Underwriters have a 30-day lock-up period, the shortest [12] - Resale must comply with Rule 144 even after the lock-up period ends [12] - Special entities like SPAC sponsors have longer lock-up periods as defined by agreements [12]