Just to supplement, the dense trading area, there are several images in the chart, they didn't display after uploading, don't blame me.

Teaching a person to fish is better than giving them fish; whether to have fish or the skill to catch fish, weigh the pros and cons yourself.
Any materials in the picture are pieced together by me temporarily, with no reference value, only for learning use.
I will explain some of the most classic and practical formations for everyone's learning and exchange. If I make a mistake, please forgive me and correct me.
The first type U formation
The U formation is relatively common; generally after a significant pullback, it starts to stabilize and then restarts, this U formation will basically appear.

It's best to use the daily line for this formation; if you don't use the daily line 👀, it basically has no reference value or significance.