20 Hit Horror Movies NOBODY Saw Coming

Even accepting the viral popularity of Kane Parsons' web series Backrooms, few could've anticipated the genuine mega-hit his A24-backed feature-length debut would become.

While it was always sure to turn a profit on its tiny $10 million budget, would anyone have been surprised if it topped out at a solidly successful $100 million globally?

But Backrooms ultimately ended its run with an incredible $401 million worldwide, in turn becoming A24's highest-grossing film ever, while the 20-year-old Parsons became the youngest filmmaker in history to take the #1 spot at the North American box office.

We've seen so many viral sensations fail to take flight when adapted to the big screen, but Backrooms was a perfect storm of factors - Parsons being allowed to direct while being mentored by a host of genre veterans, A24 producing, the current popularity of liminal horror online, and the film becoming a must-see event through strong word-of-mouth.

With a Backrooms sequel already confirmed to be in development, it'll be interesting to see if Parsons can pull off the seemingly unthinkable feat of topping this level of commercial success.