A24 has had a banner year in 2026, but one of its most surprising success stories isn't a big-budget blockbuster—it's a whisper-quiet horror film that's now making noise on streaming. Undertone, a micro-budget chiller directed by Ian Tuason, has officially become the most-watched movie on HBO Max in the U.S. as of July 2026, outperforming heavy hitters like A24's How to Make a Killing and even Steven Spielberg's Ready Player One.
Released in theaters on March 13, Undertone opened in third place at the domestic box office but proved to be a steady favorite. With a production budget of just $500,000, the film went on to gross $21.5 million worldwide—a staggering 43x return on investment. That's even more impressive when you consider that A24's other 2026 horror hit, Backrooms, earned $330 million on a $10 million budget (a 33x return). But Undertone's journey didn't end in theaters. After leaving screens in April, the film found a second life on PVOD, and now its streaming debut on HBO Max has cemented its status as a sleeper hit.
Critics have been raving about Undertone since its release. Ross Bonaime of Collider called it "one of the scariest films you'll ever hear," highlighting its innovative use of sound design to build tension. The film's strong word-of-mouth has been key to its success, drawing in audiences who crave a truly unsettling experience. For fans of underrated horror gems, Undertone is a must-watch.
A Micro-Budget Marvel
What makes Undertone's streaming triumph even more remarkable is the context of 2026's horror landscape. While Backrooms made headlines for its viral box office run and its 21-year-old director Kane Parsons becoming the youngest filmmaker to top the North American box office, Undertone quietly proved that you don't need a massive budget to terrify audiences. Its $500,000 budget is a fraction of what most horror films cost, yet it delivered scares that rival the genre's biggest names.
The film's success on HBO Max also speaks to the platform's growing appetite for original and acquired horror content. In a month where Nielsen ratings are dominated by dramas and blockbusters, Undertone has carved out a niche as the go-to streaming choice for horror fans. It's a testament to the power of smart marketing and genuine word-of-mouth in an era of algorithm-driven recommendations.
How Does It Compare to Other 2026 Horror Hits?
While Undertone's 43x return on investment is impressive, it's not the most profitable horror movie of the year. That title belongs to Focus Features' Obsession, directed by Curry Barker, which turned a sub-$1 million budget into $374 million worldwide. Obsession has broken multiple records and features a breakout performance from Inde Navarrette, who is already generating Oscar buzz. But for sheer streaming dominance in July 2026, Undertone is the film to beat on HBO Max.
If you're looking for more horror that pushes boundaries, check out our list of the most unpredictable movies ever ranked—you'll find plenty of twists and turns to keep you on edge.
Undertone is streaming now on HBO Max. Stay tuned to ShowtimeSpot for more updates on the year's biggest streaming sensations.
