Previous research has shown that when teachers in segregated school markets change jobs, they transfer toschools with similar pupil composition as the school from which they transferred. One explanation for thisimmobile mobility is that teachers develop context-related professional principles only suitable for one type ofschool context. This is conceptualised as a professional disposition. From interviews with secondary school-teachers, three different types of professional disposition have been discovered: pragmatic, idea-driven andtraditional. In this paper these are presented and related to a school market with reinforced school segregationand increased pedagogical and organisational diversity.