I hear these all the time: 1. Non-zero sum 2. Market efficiency 3. Everything is priced in 1 only makes sense if you are the market as a whole (

I hear these all the time: 1. Non-zero sum 2. Market efficiency 3. Everything is priced in 1 only makes sense if you are the market as a whole (you are not), not the one who is making the more informed decisions. 2 is true and actually a good thing for trading. It means there will be less noise vs signals. 3 doesn't matter if you are the market maker or you know the patterns caused by the "pricing in" and react to them.