The profit taking between traders and investors is different, but in principle it must have the price target. Before we buy/sell in the market, we must have a careful plan so that we can stay in the market for a long time.
The market is very dynamic. No one in this world can accurately predict the direction of the market. If you are absolutely sure of the prospects of the portfolio you hold, then I don’t recommend selling everything. If you are not sure, it is best to take all profits and mix in a new portfolio that is still promising. The market will always go through a "bearish-sideways-bullish" cycle, so we need to learn to take profit/stop loss.
Sometimes what is said to advise others, it is we who are trapped in a red market circle and do not have time to make profit targets. In my opinion, as long as the market is in the Bull zone, of course there is a possibility that something close to profit will happen.
But the problem is that we often don't pay attention to the potential in the future, only targeting trade. I agree with you, that don't sell everything in order to set aside for price movements that sometimes surprise surprises, take a 5-% profit share and use the rest to put the next price.