We employ the individual‐opportunity nexus perspective to conceptualize entrepreneurial commitment of academic scientists as the pursuit and attainment of external grant funding. We develop and test a model of network characteristics and cognitive biases that predict the likelihood that scientists will commit to a grant opportunity and the likelihood of receiving an award. Using data from our national survey of faculty, we find that the illusion of control and overconfidence reduce grant submissions but increase awards. Collaboration network size increases submissions and awards. Strong ties are positively related to submissions and smaller networks of strong, highly capable collaborators receive more awards.