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.
I think it’s good to have a price target, you actually need to know what you want to achieve and target on that. Then another thing is that we also need to know when the market is going or being bullish, and when you have reached your target, you need to have a little patience and still hold some of your assets. You can decide to sell maybe 50% of what you’re holding or even 20% of it, and then leave the rest to keep growing. And if eventually the market becomes bearish, you can then sell some of the remaining ones and get your profit before you lose all of them. So you really have a good point here.