I am not a trader. Here is my uneducated attempt: a bubble is the increase in price of an asset caused mainly by the demand due to expected continuing increase in price. Good enough?
From what I see, these things only make sense in retrospect, or with the help of insider information. You are brave to make predictions, although that's easy without providing a time frame.
As far as I am concerned, yes, this is a good time to sell because I bought them and mined them cheaper. If the price next week shoots up or drops down, I won't play captain hindsight with "should've" or "told you so" - my decission to sell was good, and based on what I knew for sure.
This I can agree with.