6 Underground is constructed in a way that sets up a movie franchise where each installment could follow the team on a new globetrotting mission to take out another corrupt leader. There are plenty of potential next targets pinned up on the walls at the group's headquarters, and the movie directly sets up a sequel with its final line, when Reynolds' character says, "I am One, but I'm not done."
Ryan Reynolds has openly talked about what he'd like to see in a sequel, telling Screen Rant, "I think it'd be fun to just get some sort of Thomas Crown vibes in there, like an old-school kind of heist. Like Eastern Europe kind of heist movie."
So why hasn't Netflix announced a sequel yet, since there's obviously consumer demand and filmmaker intention for one? It probably comes down to scheduling.
Ryan Reynolds is one of the busiest actors in the business. Most recently, he was filming another star-studded, big-budget Netflix movie, an untitled sci-fi film from Stranger Things' Shawn Levy, which is one of many projects he has in the works, according to Screen Rant. And Michael Bay is currently working on a Speed-style thriller with Jake Gyllenhaal called Ambulance, which is slated for a February 2022 release, according to Deadline.
It seems like the people behind 6 Underground are feeling no urgency to make a sequel, and they'll get to it if and when they get to it. Plus, COVID-19 precautions have made movies more expensive and complicated to make, especially movies that film on multiple continents like 6 Underground. Netflix and studio partner Skydance would have to weigh how much 6 Underground 2 would cost to make versus how many people they predict would watch it. If they decide it's worth it, they'll make 6 Underground 2 happen.
