This weekend’s two biggest movies were both directed by YouTubers

The YouTube-to-prestige-horror pipeline is looking very strong this weekend. Taking the number one spot at the box office is “Backrooms,” a feature film expansion of Kane Parsons’ series of YouTube videos featuring eerie found footage of a mysterious office space (drawn from a 4chan thread ) that defies physics. Directed by Parsons, “Backrooms” will bring in an estimated $81 million at the domestic box office this weekend alone. That’s the biggest opening by far for indie studio A24 — the previous record was held by “Civil War,” which made $25.7 in its first weekend of release. The number two film, “Obsession,” is pulling off something that’s arguably even more impressive. True, its estimated weekend total is a mere $26.4 million — but the movie (about a romantic wish gone nightmarishly wrong) already made more money in its second weekend than its first, and now its third weekend is set to grow another 10 percent. For context, most wide release films normally fall between 50 to 70 percent in their second weekend; last year’s “Sinners” was considered an extraordinary word-of-mouth success because it fell less than 5 percent. Outside of Christmas releases (which have more staying power, thanks to the holidays), growing from weekend to weekend is unheard of — according to the Hollywood Reporter , “Obsession” is the first film since 1982 to grow on both its second and third weekends. …