I.O.I released their third EP, I.O.I : LOOP, on May 19, 2026, reuniting to mark their tenth anniversary, with "Suddenly" as the title track. "Suddenly" is a synth-pop song about the rush of reconnecting with someone after a long time, co-written by member Jeon Somi. The project group, first formed in 2016, gathered nine of its members for the release.
Each point is a rolling 30-day score ending on that date, sampled weekly. May differ from the window composite above.
I.O.I was a South Korean girl group formed through the 2016 Mnet reality competition "Produce 101," in which the lineup was chosen by viewer voting from a pool of 101 trainees. The eleven-member group included future stars such as Chungha, Kim Se-jeong, Jeon Somi, and Kim Doyeon. They debuted on May 4, 2016 with the EP "Chrysalis" and its single "Dream Girls," and promoted as a full group and as a sub-unit. As a temporary project group, I.O.I were active for less than a year before disbanding in early 2017, after which members returned to their agencies or debuted in other groups. Despite their short run, I.O.I proved the commercial power of survival-show-formed groups and influenced a wave of similar projects across the industry. They are remembered as one of the most influential project groups of K-pop's third generation.