This paper claims that the form hu marks contrastive topic in Eastern Cham (Austronesian: Vietnam) by means of its other uses as an existential closure and verum focus marker. The existential closure use closely tracks with the form described in Bura (Chadic: Nigeria) by Zimmermann (2007). The verum focus use is largely parallel to the form có in Vietnamese (e.g. Tran 2016). It is proposed that an extension of verum focus semantics adapted to the syntactic distribution of the existential marker gives rise to contrastive topic marking. Finally, it is noted that contrastive topics remain in situ, unlike non-contrastive topics, which undergo topicalization to the left periphery.