BTS's song 'ARIRANG' is reportedly dominating various music charts around the world, including those in the UK and US. The group is said to have achieved significant milestones on platforms such as Billboard, YouTube, and iTunes. The extent of BTS's chart dominance is unclear, with some outlets reporting that they have topped multiple charts, while others mention the success of 'ARIRANG' alongside another song, 'SWIM' or 'Come Over'.