Stock market participation is found to be positively related to cognitive, as well as non-cognitive ability, controlling for wealth, income, age, and other demographic and socioeconomic factors. Interestingly, the effects are of economic significant magnitudes, e.g. participation is on average 11.49% larger among those with high compared with low cognitive and non-cognitive abilities, and holds also when controlling for individuals risk preferences. The later indicates that cognitive and non-cognitive abilities have a role in affecting financial decisions also through non-preference driven effects. Limitations in non-cognitive ability do further explain non-participation among affluent individuals.