Markiplier’s “Iron Lung,” an adaptation of an indie video game, pulled in $18.19 million at the domestic box office on opening weekend.

Mark Fischbach, also known as Markiplier, in "Iron Lung."Markiplier / Courtesy Everett Collection

A YouTuber`s self-financed and self-distributed sci-fi horror film is overturning industry expectations after it made it big at the box office over the weekend.

"Iron Lung," an indie video game adaptation from YouTuber Mark Fischbach (better known as Markiplier), pulled in $18.19 million at the domestic box office on opening weekend, according to final figures from Comscore. That`s more than six times its reported $3 million budget.

The film, which Fischbach wrote and directed, played in 3,015 theaters across the U.S. and Canada. It came in a close second to the Sam Raimi-directed horror-thriller "Send Help," which took the top slot at the box office by amassing $19.1 million domestically. It also surpassed the Amazon MGM Studios release "Melania: Twenty Days to History," a documentary following the first lady, which rolled out in over 1,500 theaters in North America.

A growing spectrum of creators - from Addison Rae to MrBeast- have leveraged their social media prowess to make headway in traditional film, TV or music. Fischbach has more than 38 million subscribers on YouTube, where he has built a massive brand around his gaming playthrough and commentary videos since he joined it in 2012.

"To see really savvy creators and influencers ... parlay their small-screen YouTube success either onto traditional television or onto the big screen is remarkable, and I think we`re going to see more of it," said Paul Dergarabedian, Comscore`s head of marketplace trends. "You never know where the next big hit is going to come from."

Based on a 2022 sci-fi horror game of the same name, the movie follows a convict, Simon, who must pilot a submarine on a faraway moon, navigating its ocean of blood after an apocalyptic event caused all planets and star systems to vanish.

Fischbach stars as Simon, alongside fellow YouTuber Seán William McLoughlin (better known as Jacksepticeye), who also played the original 2022 game on his channel.

The game`s creator, David Szymanski, appeared shocked at the film`s popularity, posting "What the f--" on X.

In a YouTube livestream Sunday, Fischbach also got emotional seeing the box office numbers. Competing with the likes of Raimi, he said on the stream, felt like "kind of a hero moment to showcase indie filmmaking is possible."

"And maybe if that could inspire someone to keep making films, that`d be pretty cool," he said, composing himself through tears. "And maybe if it could open up a door for other people to do their projects independently and know that there could be success in it, I think that`d be pretty cool. I think that might be actually really cool."

Like many who ventured from YouTube into traditional Hollywood, Fischbach has used his platform to experiment with professional filmmaking. He wrote and directed the YouTube Original comedy films "A Heist with Markiplier" (2019) and "In Space with Markiplier" (2022).

In an industry that often puts the rise of YouTube and streaming in competition with movie theaters, Dergarabedian said, "Iron Lung" provides some evidence that the two can instead be viewed as complementary experiences. There`s a place for streaming, he said, but people still go to movie theaters for a unique big-screen experience.

The box office hit also stirred some discussion online about the potential for digital creators to wade into professional filmmaking. An X user wrote that Fischbach "has opened doors for other youtubers/content creators to be taken seriously within the film world," adding that the film industry "better be taking notes."

Despite its relatively low budget and small marketing effort, Fischbach`s movie had a few factors working in its favor, Dergarabedian said. It opened after a relatively quiet January for theaters, and horror as a genre has drawn high interest over the past year - 2025 was the biggest year ever for horror movies at the box office.

Still, its success surprised many. Dergarabedian said the film could become a blueprint for others aiming to execute self-financed films, which rarely make it into theaters in the first place.

"Usually, movies have to have a long run-up in terms of marketing and awareness-building to have success in a movie theater," he said. "But this is breaking all the rules."