The phrase comes from the fan culture around Detroit hip hop duo Insane Clown Posse, whose devoted followers call themselves Juggalos. Whoop whoop works as both a greeting and a shout of solidarity, shouted back and forth at concerts and at the annual Gathering of the Juggalos. As clips spread on YouTube, TikTok and soundboard sites, the short chant became shorthand for Juggalo identity and unapologetic hype, even for people who have never attended a show. Its simplicity is why it still cuts through in short edits today.