The International Baccalaureate's (IB) branding and reputation targets academic high achievers aiming for university entrance. This is an empirical examination of the growing popularity of this transnational secondary credential amongst local populations in Australia, focusing on its uptake across the community, and the discourses underpinning its spread and popularity. This paper reports on online surveys of 179 parents and 231 students in schools offering the IB as an alternative to Australian state curricula. It sets out to understand the social ecology of who chooses the IB and who it chooses. Statistically significant differences between IB and non-IB choosers were found in terms of family income, parent education, student aspirations, transnational lifestyles and neoconservative, neoliberal and cosmopolitan beliefs. The analysis demonstrates how the reproduction of advantage is accomplished through choice behaviours in stratified educational markets. (Contains 8 tables.)