In the previous post, we validated the effectiveness of IVP screening using 5 years of data: the high threshold group outperformed the low threshold group, with the best Sharpe ratio of 7D > P80 reaching 0.61. However, there is a problem: 6 total losses in 2021 and 10 total losses in 2024. This is because the IV spike in a bull market may come from FOMO chasing rather than panic. Although there are countless examples of FOMO chasing leading to crashes, these crashes tend to reverse quickly, which is very unfavorable for weekly puts held to expiration; in a bear market, the IV spike reflects market panic more, and the downtrend is more persistent, making puts more effective. The solution is quite simple; we can actually use the classic bull-bear boundary of the entire market, MA200, to filter. If the price is above MA200, even if the IVP reaches the threshold, we do not buy puts. We only trigger trades when the price is below MA200 through the IVP threshold. Taking the best Sharpe ratio of 7D > P80 as an example: after adding the bull-bear boundary, the number of trades decreased from 40 to 18, but the profit amount remained almost unchanged, with ROI increasing from 2.3× to 4.9×, and the longest losing streak reduced from 26 to 10. From the matrix chart below, it can be seen that all thresholds achieved a 2-3 times performance improvement; buying puts in a bear market is truly following the trend!