This thesis contributes to the currently still sprawling literature on the force of sustainable investing together with the “Big Five” personality structure (Openness to Experience, Conscientiousness, Extraversion, Agreeableness and Neuroticism). By investigating which personality trait, based on the Big Five personality taxonomy, that was willing to exchange revenue for a higher ESG rating in a hypothetical investment fund, we were able to determine when private investors were willing to pay more for a more sustainable investment. We use new data from our own questionnaire where the respondents are adult individuals residing in Sweden who has invested in the stock market. The data was analyzed with an econometric approach and for the regression ordinary least square and tobit was used. The results revealed that two personality traits (conscientiousness and agreeableness) tended to be less interested in sustainable investments, as they were not willing to pay for a fund with a higher ESG rating, unlike Openness to Experience, where the willingness to pay was high. The other two traits also showed a positive relationship and thus willingness to trade revenue for sustainability. This thesis contributes to the knowledge on how the personality of the private investors can motivate investment decisions and the preference of companies they invest in.