This paper demonstrates the relevance of consumers’ susceptibility to interpersonal influence (csii) in an investment context. In study 1, a survey of individual investors, investment-related knowledge, psycho-social risks, and social needs emerge as antecedents that explain investors’ susceptibility to informational and normative influence. In turn, susceptibility to normative influences increases transaction frequency, whereas susceptibility to informational influences decreases transaction frequency. The experiments in studies 2 and 3 indicate the impact of interpersonal influences on consumers’ investment decisions in a voluntary (free choice) and involuntary (confrontation) setting and check whether csii moderates the impact of interpersonal influences. Consumers’ investment choices are consistently influenced by the information and opinions of others, whereas csii only strengthens the impact of interpersonal influence in a voluntary informational setting.