Human intellectual development is grounded in dialogue and collaboration. This study examined how students' collaborative epistemic actions evolve and expand in online collaborative learning meetings and how such actions may enhance students' agency in advancing the conceptual understanding of learning tasks or problems in an institutional massive open online course (MOOC). As data, recordings of students' online video meetings were analyzed using interaction analysis and interpreted using the cultural-historical theory of learning. The findings revealed that students engaged in four epistemic actions and several epistemic activities: (a) co-orienting (planning actions of engagement), presenting (sharing ideas explicitly), discussing (assessing and expanding ideas), and summarizing (reflecting and structuring). These collaborative epistemic actions (CEAs) evolved when students presented, explained, claimed, and vetted their epistemic positions related to creating the examination assignment in the online learning meetings. These jointly developed CEAs allowed students to position and contribute to the learning process according to their willingness and preparedness. By contributing to solving problems or expanding understanding, students can enact their epistemic agency, which becomes prominent in collaborative learning. Online collaborative meetings may foster students' co-agency or engaged agency as students co-create a shared understanding of how to solve problems, leading to emotional, cognitive, and conceptual becoming. Practitioner Notes 1. Collaborative learning meetings may profoundly affect student learning in institutional MOOCs, in which they remain remotely located. 2. Dialogue and collaboration shape human intellectual development. 3. Students can enact, realize, develop and expand their epistemic agency when they engage in a collaborative process of solving problems. 4. Developing and advancing the conceptual understanding of learning tasks or problems require students to enact their engaged epistemic agency. 5. Students can enact their epistemic agency to develop a scientific understanding of learning problems in higher education.