股票股指期权：隐波与标的呈现负相关，可考虑熊市看跌价差保护

Report Date - The report is dated December 4, 2025 [1] Core Viewpoint - Stock index options: Implied volatility is negatively correlated with the underlying, and bear put spread protection can be considered [2] Key Data Summaries Underlying Market Statistics - Indices and ETFs: The closing prices of various indices and ETFs showed different changes. For example, the Shanghai Composite 50 Index closed at 2974.34, up 11.26; the CSI 300 Index closed at 4546.57, up 15.52; and the CSI 1000 Index closed at 7248.66, up 0.38. Trading volumes also varied, with some experiencing decreases such as the Shanghai Composite 50 Index with a trading volume of 36.28 billion hands, down 2.24 billion hands, and others like the Huaxia Science and Technology Innovation 50 ETF having an increase in trading volume to 22.21 billion hands, up 3.96 billion hands [3] Option Market Statistics - Trading Volume and Open Interest: The trading volumes and open interests of different option types changed. For instance, the trading volume of Shanghai Composite 50 Index options was 19,955, down 5,187, and the open interest was 68,657, up 1,483. The trading volume of CSI 1000 Index options was 189,851, up 201, and the open interest was 328,006, up 5,770 [3] - PCR Ratios: The VL - PCR and OI - PCR ratios also had different values. For example, the VL - PCR of Shanghai Composite 50 Index options was 63.02%, and the OI - PCR was 70.50%. The VL - PCR of CSI 1000 Index options was 82.52%, and the OI - PCR was 89.92% [3] Option Volatility Statistics - ATM - IV, HV, and Other Indicators: The at - the - money implied volatility (ATM - IV), historical volatility (HV), skew, and VIX of different option types showed different changes. For example, the near - month ATM - IV of Shanghai Composite 50 Index options was 11.06%, up 0.40%, and the 20 - day HV was 10.79%, down 0.27%. The near - month ATM - IV of CSI 1000 Index options was 17.29%, down 0.39%, and the 20 - day HV was 22.68%, down 0.18% [6]