This study investigates Singaporeans' unrealistic optimism with event valence and event likelihood estimations for self versus in-group (best friend) and out-group (average student and average person) target persons among 180 Singaporean undergraduate students. Participants are unrealistically optimistic for four negative events and one positive event in out-group comparisons. The more similar the target person, the more unrealistic optimism is displayed. Perceived controllability positively correlates with unrealistic optimism. In in-group comparisons, participants are pessimistic for one positive and three negative events. This can be attributed to self-defense, kiasu (fear of failure), and implicit self-enhancement. Implications for marketers are discussed.