At the beginning, the granularity research is coarse, it doesn't matter, and it is slowly eliminated. For example, you can screen by industry, then remove some according to business model, and then remove some according to assets and liabilities, etc. In each round of screening, only the best ones are retained and the poor ones are removed.Think about it, at that time, you can get rid of the same workplace as cattle and horses, and get rid of the infinite complexity of life. You don't have to bow to anyone, you don't have to smile, and you can travel around the world and do anything you want with a mobile phone.
Your idea may be, anyway, if the east is not bright and the west is bright, it won't be a loss. If you think about it the other way around, you may feel terrible. It's not dark in the east and dark in the west, and it will always be dark, especially when the market falls.The logic of profiteering is less but better.If you are wrong, because your position is small and the loss of a single stock is relatively small, it is easy for you to cut your meat, because you don't feel bad, but if many stocks cut their meat like this, it will be a lot of money, and it will be a big loss.
If you want to control the smoothness of the overall account, the position can be appropriately small, such as a medium position, and some funds can be reserved for better opportunities. In this way, you can attack and defend. You expect to go up, but you are not afraid of going down, because you are still a potential buyer, and you can do it more easily.In the early stage of investment, few but fine are passive and need your control. Although you don't know what's right yet, you already know what's wrong, so it will be hard to control your behavior with willpower, which is certain and insurmountable.If you are wrong, because your position is small and the loss of a single stock is relatively small, it is easy for you to cut your meat, because you don't feel bad, but if many stocks cut their meat like this, it will be a lot of money, and it will be a big loss.