“It almost makes me nervous,” Blum said, then leaned back and looked up. “The idea of working with you.” He paused. “But anything you want to do, I’m in. I’m in, I’m in, I’m in.”

To save time and money, Blum does a lot of his work as a producer — making calls to actors, directors and studio heads — in the back of a gray Ford cargo van that he has equipped with wide plush captain’s seats, two large video displays and window blinds that are nearly always drawn shut. Often, in the middle of a call, the van will stop, the automatic sliding door will open, the aggressively bright Los Angeles daylight will pour in and there Blum will be: at some suburban theater for a test screening of one of his movies; at the lot of Universal Pictures, which markets and distributes most of those movies; outside his downtown apartment, where he lives with his wife, Lauren Schuker Blum, a journalist turned screenwriter, and their 2-year-old daughter; or at the office building in Filipinotown that once housed Cat Fancy magazine and now serves as the headquarters of Blumhouse Productions, which since he started it in 2000 has made 82 movies.

Blum has more or less always been a producer — his first feature credit was in 1995 at 26, for his college roommate Noah Baumbach’s first movie, “Kicking and Screaming.” Since then, Blum has worked on a variety of independent films, including a contemporary adaptation of “Hamlet” in 2000, with Ethan Hawke in the title role. But for the last eight years, Blum has primarily made horror movies, few of them costing more than $5 million, and some of them — including the “Insidious” and “Purge” franchises, as well as the M. Night Shyamalan comeback, “Split” — grossing into the hundred millions.

Horror movies occupy a special place in the hearts of producers. They are cheap, their fans don’t demand well-known actors and the ratio of risk to reward can be astonishing. “Night of the Living Dead” cost $114,000 to produce in 1968 and has since grossed at least $30 million; “The Blair Witch Project” cost $60,000 to produce in 1999 and has since grossed $249 million. Blumhouse’s own “Paranormal Activity,” shot in one house with two unknown actors and almost no crew, cost just $15,000, yet its box-office return since its 2009 release has been $193 million, a return on investment of about 1.3 million percent.

Blum’s approach represents a particularly enterprising way out of the dilemma in which Hollywood finds itself in the age of endless “Transformers” sequels and “Spider-Man” reboots. A typical blockbuster can cost around $200 million, with another $100 million for marketing. At that rate, the studios can’t afford to make a lot of movies, which means the ones they do make can’t fail. This year Disney will release just seven movies, and all but one of them will be a sequel or a reboot. Blum, by contrast, makes a lot of movies on small budgets, and many of them never even go into wide release. Because the production cost is low, he can consider other options for movies that don’t seem likely to break big — ones that don’t require an additional multimillion-dollar marketing commitment but could still recoup the initial investment with maybe a little extra as well. Some Blumhouse productions appear on a few hundred screens, often targeted at narrow fan niches. Others might appear in a festival or two then get sold to a streaming service like Netflix.

Some projects fizzle — “Jem and the Holograms,” for instance, had the worst opening weekend of 2015, just $1.4 million. But when Blum sees a glimmer of something bigger, he can pole-vault his low-budget films into wide release with the help of a major studio. “Get Out” is a critical success thanks to the specific genius of Jordan Peele, but the reason you saw it in a packed theater is that Universal spent $20 million to $30 million on marketing. (The day after Blum spoke to the Sundance donors, he delivered a rented ice-cream truck to Universal’s marketing department, as a thank-you.)