Portfolio Allocation: It is never a wise decision to put all your eggs in one basket as you may lose it all in one go. The same goes with trading. If you invest all your assets in one type of trading, you may face a huge loss for any risk in that trading field. That’s why experienced trading advisors suggest properly plan and allocate your assets in different profit-making fields so that the returns and risks remain properly balanced to get you a consistent profit.
Another great method is to set up the thresholds to which you can bear your losses before selling and mostly it is a percentage of the initial purchase price. This is something you can gain from experience and it will help you greatly in your trading.
It is also recommended by experts to lift the stops every time the stock hitting a new high. And it is also recommended to put the stops on a closing basis instead of putting it intraday otherwise you may be shaken out of stocks that drop suddenly only for a quick rebound such as in a flash crash.
The best way to determine the size is that the position size to be proportional to the expected outcome which is the probability of gain making multiplied by the gain amount, plus the probability of loss-making multiplied by the loss amount.
Following this consistently for many months and years, you can adjust the risks of buy and hold and can get a good performance.
This method is followed by both experts and beginners for many types of assets.