this as an perfect example on how to 波段

The chart I am posting here has been pretty much the same for the 2-3 weeks. There are 3 places where you could take profit  (marked as B, ii, and iv in this chart).

Now, do we know for sure that mrket will pullback from there? 

Of course not. No one knows for sure where market will go. But If you are playing with  波段，you want to sell your position (or at least some of your position) near those points, even though market is rising at that time. 

• If market continue to rise and break those resistance points, you can always buy your shares back at slightly higher price but play for the next up wave
• If market drops, you have A: much more capital to deploy and B: Emotionally better positioned as you have already taken the profit. This allows you to be confident to buy at the low point of next wave.

Of course, if you want to 定投，ignore everything here :)