股市放量回调，股指冲高回落

1. Report Industry Investment Rating - Not provided in the content 2. Core Viewpoints of the Report - On September 18, 2025, the stock indexes fluctuated and declined throughout the day, with the Shanghai, Shenzhen, and Beijing stock markets having a total turnover of 3166.6 billion yuan, a significant increase of 763.7 billion yuan from the previous day. The decline was mainly due to large stock price increases and significant valuation improvements, causing investors to lose confidence in chasing prices and increasing their willingness to take profits. [3] - In the medium to long term, stock indexes are strongly supported by favorable macro - policies and net inflows of funds. Given the weak credit and inflation data in August and the slowdown in consumption growth, there is a high expectation of policies to stabilize demand, with the key window period for policy introduction expected to be in October. The significant increase in non - bank deposits in July and August and the high - level operation of margin trading balances indicate continuous inflows of incremental funds into the stock market. [3] - However, due to the significant increase in the valuation of some stocks, there is still a willingness among profitable funds to take profits, leading to short - term technical adjustment pressure on stock indexes. The subsequent focus should be on the game between the rhythm of profit - taking and the fermentation of policy expectations. In general, stock indexes are expected to experience wide - range fluctuations in the short term. [3] - Currently, the implied volatility of options has increased. Considering the long - term upward trend of stock indexes, investors can continue to hold bull spreads or ratio spreads. [3] 3. Summary According to Relevant Catalogs 3.1 Option Indicators - On September 18, 2025, most ETFs and stock indexes declined, except for the科创 50ETF and the 易方达科创 50ETF, which rose by 0.69% and 0.64% respectively. For example, the 50ETF fell 1.30% to 3.048, and the 300ETF (Shanghai Stock Exchange) fell 1.27% to 4.594. [5] - The trading volume PCR and open - interest PCR of various options changed compared to the previous trading day. For instance, the trading volume PCR of the Shanghai Stock Exchange 50ETF options was 78.41 (previous day: 87.34), and the open - interest PCR was 73.26 (previous day: 76.66). [6] - The implied volatility of at - the - money options in September or October 2025 and the 30 - trading - day historical volatility of the underlying assets were provided for different options. For example, the implied volatility of at - the - money options of the Shanghai Stock Exchange 50ETF options in September 2025 was 19.35%, and the 30 - trading - day historical volatility of the underlying asset was 15.12%. [7] 3.2 Relevant Charts - Multiple charts were presented for different types of options, including the trend of the underlying asset, volatility, trading volume PCR, open - interest PCR, implied volatility curve, and the implied volatility of at - the - money options for different terms. For example, for the Shanghai Stock Exchange 50ETF options, there were charts showing its trend, volatility, trading volume PCR, etc. [9][11][13]