In recent years, a growing number of wealthy families entering the equity market have been seeking direct investments. But how do these actively investing families (family investors, henceforth) behave compared to non-family investors such as private equity (PE) firms? Answering this is particularly interesting from the investee firms’ perspective of family businesses, as the mindset of family investors might be more similar to their own. However, studies so far have neglected to distinguish between different investors in family firms. Thus, this conceptual paper aims to improve the understanding of family and PE investors and to consider the conditions and decision criteria under which family firms seek an external investor. To fulfil this goal, the two investor types are systematically compared, and based on multiple theoretical perspectives, a model of which investor type would best fit with family firms and their specific challenges is proposed. Thereby, we argue that the two investor types might be suitable partners for the investee firms depending on the challenges they face.