Many fan behavior studies leave applications for strategic sport marketing as afterthoughts. Likewise, studies of sport marketing practices often ignore the complexities of fan psychology. The purpose of this work is to propose a new model that accurately categorizes sport products, better recognizes fan behaviors, and provides sound guidance to sport marketers. The work applies the well-established theory of portfolio management (wherein, investors strive to receive higher returns with lower risks by managing an assortment of investments). Herein, sport fans are viewed as investors that “buy,” “hold,” and “sell” athletes and teams. From sport to sport and season to season, fans manage their portfolios in line with personal goals, values, and social influences. The emergent Sport Marketing Portfolio Matrix uses axes of brand relevance and fan behavior and provides a solid foundation from which to launch myriad studies. Research-worthy propositions are derived and discussed throughout the work