When price is captured between a ceiling and a roof, its better to BLSH. what does BLSH means?
It means Buy low, Sell high. when price reaches the top of trading range, you can bet that it goes down. You might say "why? Isn't that at some point it will break out of this range and start to trend?"
I will say to you yes, BUT most of attempts to break out will fail. You can see in chart that how many times EURCAD tried to break out of her prison, but it couldn't do it.
So, if you see price reaches top of trading range AND you have right signal you can short.
Here in 22nd of December you had you signal. in that day price tried to reach higher but it did reverse and came back, the long tail on top of the candle says that to us.