We study a college admissions problem in which colleges admit students in the early and regular admissions, and students’ types are revealed sequentially through the admission process. We show that a less popular college has an incentive to preempt students based on partial information about their types in the early stage, especially when the quality gap between colleges is small or colleges’ capacity is large. The preemptive movement of the less popular college makes a more popular college admit students in the early stage who otherwise would admit students in the regular stage after observing full information about students’ types. This makes the admission more competitive and the matching between colleges and students less assortative.