Although scholarship has demonstrated that market categories offer important signals to entrepreneurs about which goods and services are valued, little research has considered how entrepreneurs make sense of and exploit opportunities when contestation over category meaning persists. Using the emergent U.S. biodiesel market as a context, we present a framework to explain how the salience of different stakeholder frames shapes entrepreneurs’ perceptions of market opportunities and influences their market-entry strategies. By showing how framing contests affect entrepreneurial outcomes, this study illuminates the underlying cognitive mechanisms that impact market meaning and offers important implications for the literatures on entrepreneurship, market-category evolution, framing contests, and grand challenges.