除了股票简称后加标识“U”，上交所解释何为科创成长层

Core Viewpoint - The China Securities Regulatory Commission (CSRC) has issued guidelines for establishing a "Growth Layer" within the Sci-Tech Innovation Board to enhance the inclusivity and adaptability of the system, with supporting rules from the Shanghai Stock Exchange (SSE) [1][2][3] Group 1: Establishment of the Growth Layer - The Growth Layer aims to serve technology companies that have significant breakthroughs, broad commercial prospects, and substantial ongoing R&D investments, particularly those that are currently unprofitable [3] - A total of 54 unprofitable companies have successfully listed on the Sci-Tech Innovation Board over the past six years, generating a combined revenue of 1,744.79 billion yuan in 2024, with 26 of these companies exceeding 1 billion yuan in revenue [3] Group 2: Regulatory Framework - The SSE's self-regulatory guidelines for the Growth Layer will establish mechanisms in three areas: implementation standards and procedures, risk disclosure, and enhancement of information disclosure quality [4] - Companies in the Growth Layer will have their stocks or depositary receipts marked with a special identifier "U," and investors will need to sign a risk disclosure document when investing in newly registered companies [4] Group 3: Pre-Review Mechanism for IPOs - The SSE is introducing a pre-review mechanism for IPO applications to help companies manage sensitive information and reduce exposure during the listing process [5][7] - The pre-review process will not replace the formal application process and will not confirm compliance with listing conditions, but will provide feedback to issuers before they formally apply [8]