股票股指期权：隐波高开走低，看跌情绪上升，可考虑买入看跌期权保护

1. Report Industry Investment Rating - Not provided in the given content 2. Core View of the Report - On October 13, 2025, the implied volatility of stock index options opened high and trended lower, with a rise in bearish sentiment. It is advisable to consider buying put options for protection [1] 3. Summary by Related Catalogs 3.1 Option Market Data Statistics - Underlying Market Statistics: The closing prices of the Shanghai Composite 50 Index, CSI 300 Index, and CSI 1000 Index decreased by 7.65, 22.86, and 14.06 respectively. The trading volumes of the Shanghai Composite 50 ETF, Huatai-PineBridge 300 ETF, and Southern 500 ETF were 5.38 billion, 9.66 billion, and 3.87 billion hands respectively [2] - Option Market Statistics: The trading volume and open interest of most options increased. For example, the trading volume of Shanghai Composite 50 Index options increased by 7,823 to 64,550, and the open interest increased by 775 to 77,244 [2] 3.2 Option Volatility Statistics - Near - Month Options: The ATM - IV of most options increased. For instance, the ATM - IV of Shanghai Composite 50 Index options increased by 0.38% to 15.63%, and the ATM - IV of CSI 1000 Index options increased by 1.87% to 21.65% [5] - Next - Month Options: The ATM - IV of most options also increased. For example, the ATM - IV of Shanghai Composite 50 Index options increased by 0.53% to 17.69%, and the ATM - IV of CSI 300 Index options increased by 1.28% to 19.04% [5] 3.3 Option Indicator Data Statistics - PCR and Skew: The VL - PCR and OI - PCR of most options showed different degrees of change, and the skew also changed. For example, the VL - PCR of Shanghai Composite 50 Index options was 70.39%, and the skew of near - month options decreased by 2.84% to - 0.20% [2][5] 3.4 Option Charts - Volatility Charts: For various options such as Shanghai Composite 50 Index options, CSI 300 Index options, and Shanghai Composite 50ETF options, there are charts showing the volatility trends of the main contracts, including ATM - IV and 20HV [9][11][13] - PCR and Skew Charts: There are also charts showing the PCR and skew trends of the main contracts and all contracts of various options [9][14][17] - Volatility Cone and Term Structure Charts: There are charts presenting the volatility cone and term structure of various options [9][15][18]