Bitcoin is really a nice investment and despite it's volatility, there are a whole lot of investment and business opportunities in Bitcoin.
It seems from your lost you already have lots of knowledge in Bitcoin already especially when to buy and when not to buy, but the general truth is that we should always buy Bitcoin at every little opportunity that we grab.
Bitcoin has come to stay and it is the investment of the future but one thing that bothers me is the mentality that has been instilled in people as if selling Bitcoin when they make some profit is wrong and this is bad because the general concept of saving or investment is to back something to fall back when the need for money arises without bothering anyone.
I always buy Bitcoin at every instance I get, and I'm holding as much as I can.
There is nothing wrong with selling Bitcoin, but only if the holder understands when is a good time to buy and when to sell. For example, you can buy only in a bearish market using DСA, and sell only in a bullish market, no sooner than the price reaches ATН, but you also need to set realistic goals. You should not expect that Bitcoin will be able to do x10 - x20 every cycle, Bitcoin is becoming a large capitalization asset, and most likely it will change.