In this chapter we address the dynamics of capital mobilization, conversion and circularity throughout entrepreneurs’ trajectories in technology-based startups. The research explores the growth and trajectories of technology-based startups and maps out the interplay of entrepreneurs’ capital for the foundation and development of these companies. This involves four dimensions of entrepreneurial capital, namely: economic, cultural & human, social, and symbolic capital. The method is based on a multiple case study using interviews conducted with entrepreneurs from five technology-based startups located in Brazil. Results suggest that different scopes of entrepreneurial capital are interchanged and interchangeable along entrepreneurial trajectories. We note the initial importance of symbolic capital merged into social capital, and how initially this offers legitimacy in the liability of newness. The supporting role of these entrepreneurial capitals was dynamic, involving mobilization and conversion of different types of capital. We explain this as the circularity of capital.