To celebrate the premiere of IT: Welcome to Derry, HBO launched Red Balloon Day, a global stunt inspired by the franchise's most iconic symbol. Red balloons appeared across landmarks, neighborhoods, sporting events, out-of-home placements, and social media around the world, warning fans that Pennywise was near. Amplified by influencers, brand partners, and surprise appearances from Pennywise himself, the campaign transformed a simple red balloon into a worldwide cultural event.