Using a unique dataset of 44 Massive Open Online Courses (MOOCs), this article examines critical patterns of enrollment, engagement, persistence, and completion among students in online higher education. By leveraging fixed-effects specifications based on over 2.1 million student observations across more than 2,900 lectures, we analyzed engagement, persistence, and completion rates at the student, lecture, and course levels. We found compelling and consistent temporal patterns: across all courses, participation declines rapidly in the first week but subsequently flattens out in later weeks of the course. However, this decay is not entirely uniform. We also found that several student and lecture-specific traits were associated with student persistence and engagement. For example, the sequencing of a lecture within a batch of released videos as well as its title wording were related to student watching. We also saw consistent patterns in how student characteristics are associated with persistence and completion. Students were more likely to complete the course if they completed a pre-course survey or followed a quantitative track (as opposed to qualitative or auditing track) when available. These findings suggest potential course design changes that are likely to increase engagement, persistence, and completion in this important, new educational setting.