Humility, especially intellectual.
Being humble in investing isn’t about doubting yourself or believing that you are unworthy or unintelligent but it is about being humble about our intellect, it is about asking yourself if what we know or what we are doing is correct. Also are we adjusting our beliefs according to the new information being received. It is being intellectually humble.
Philip Tetlock wrote in Superforecasting that the true humility in investing is about recognizing that reality is profoundly complex, that seeing things clearly is a constant struggle when it can be done at all, and that human judgment must therefore be riddled with mistakes.
Very few investors have the nerve to say “ I don’t know” But that’s how you build humility in your investment process. If you start with “ I don’t lknow” then you are unlikely to act so boldly as to get into trouble.