Psychology is 90% of trading success ,unless trader is a robot.The human with a mind is going to execute the trades.The brain command centre makes all the trading decisions.
The evidence is there on the free internet , there are simple free profitable methods ,systems and techniques , yet 95% fail and dissapear.
If traders don't understand the mind ,how it works subconciously in trading , the traders can not have any plans for the 90% risk of underperformance due to psychology.It is with the mind where traders lose in trading due to emotions ,stress , need to be right , subconcious emotional executions ,mind traps , automatic mind in trading , beliefs in trading , subconcious errors , brain command centre shutdown during trading , brain freezing in trade executions ,the power the thought , negative wiring of human brain and it's performance in trading ,meditation , unreality reading of the real market conditions,cognitive biases in trading decisions , mental traps , benefits of patience and disadvantages of impatient traders , impulsivity , self sabotage in trading executions , stress responses , amygdala hijackings ,personality , ego and other psyche charecteristics.
Those traders who say psychology is unimportant are just useless clueless traders.