While the title mentions Seoul, the rules explicitly state that the resolution relies on data from the Incheon Intl Airport station. Incheon is coastal, and its temperatures often differ from downtown Seoul, which could easily mislead traders who do not read the fine print.

Predicting the highest daily temperature of a specific city on a particular date is highly niche. Aside from locals or meteorology enthusiasts, the general public rarely considers this, making it quite a novel and exotic market.