The analysis in this video shows that the average bear market rally over the past year has been 7.5% over 8-9days. This numbers are quite significant because if and when this happens, it'll take SPY straight into a supply zone coinciding with a cycle date. This makes it a very high probability that the market could turn around to the downside from there, and thus a very good shorting opportunity.
Thanks for this analysis of the size of various bear rallies. Well done! My recent technical analysis uses a somewhat different approach, but my proposed targets are very similar to yours it seems: