Success in investing doesn’t correlate with I.Q. Once you are above the level of 25; once you have ordinary intelligence, what you need is the temperament to control the urges that get other people into trouble in investing.
Apparently, an undocumented side effect of dope is a gross overestimation of one's own intelligence. Dopers become convinced they've hidden their stash so well a cop won't find it. They're always wrong.