中芯国际A股，突发！

Core Viewpoint - SMIC, a leading stock on the STAR Market, has encountered a sudden situation where its A-share margin financing ratio has been adjusted to zero by several major brokerages due to its static price-to-earnings (P/E) ratio exceeding 300 times as of September 30, 2023 [1][4]. Group 1: Margin Financing Adjustments - Major brokerages including CITIC Securities, Guotai Junan, and Huatai Securities have set SMIC's A-share margin financing ratio to zero, following the revised rules from the Shanghai and Shenzhen Stock Exchanges [1][3]. - The adjustment is based on the 2023 revised "Implementation Rules for Margin Financing and Securities Lending Transactions," which stipulates that A-shares with a static P/E ratio above 300 or negative values have a margin financing ratio of zero [4][5]. - Prior to this adjustment, SMIC's A-share margin financing ratio was 70% at Guotai Junan [3]. Group 2: Comparison with Hong Kong Market - In contrast to the A-share market, the Hong Kong market allows brokerages to set their own margin financing ratios, leading to a more flexible environment where SMIC's Hong Kong shares currently have a financing ratio of around 50% [1][6]. - The static P/E ratio for SMIC's Hong Kong shares is 175 times, which does not trigger a reduction in the financing ratio under the current rules [8]. - Other stocks with static P/E ratios exceeding 300 in the Hong Kong market, such as Hua Hong Semiconductor, still qualify for margin financing, indicating a disparity in regulatory approaches between the two markets [10][12]. Group 3: Investor Implications - Investors holding SMIC shares will not be forced to liquidate their positions due to the zero financing ratio, but they may face challenges in opening new positions or obtaining additional financing [5][4]. - If investors' maintenance margin ratio falls below 130%, they may be required to deposit additional collateral or liquidate some assets to maintain their positions [4][5].