How to build a reliable trend trading system? Let's discuss

If you want to make money in trading, what principles do you need to understand?

What is your basis for entering the market?

What are the common operating modes of thousands of trading studios, and how do they support themselves?

I partnered with a friend to do asset management for a year, and then it all collapsed. Is there any colleague to share with you? I also want to try again, before I try, I would like to ask everyone's suggestions and experiences

If you have a bad mentality, does this mean that you are not suitable for trading?

Everyone talks about whether the news is bullish or bearish. Why does the market still go in the opposite direction?