I agree with some earlier comment that we'd better wait more for a safer entry. The market keeps making new microstructures these days. For option swing traders like me, it requires more time to watch the market, which is tiring. After clearing the short position entered on 10/24 this morning, I decided to wait. Though I missed the strong rebound, I may have a better view about the trend now.
The dashed line is a virtual support. Bears needs to break it hard to reach the channel low. This actually makes trading easier for bears. The downward space is big enough for good profit even if you wait for spy to decisively break the dashed support. Or you could establish another short position when spy touch the channel high above, which could be due tomorrow. Either way gives us less risk to trade as a bear compared to a bull.