John Magaro, who starred in David Chase’s first feature “Not Fade Away” alongside the late James Gandolfini, appears in two of December’s most notable releases. One is Todd Haynes’ “Carol,” with Cate Blanchett and Rooney Mara. The other is “The Big Short,” Adam McKay’s ensemble comedy about the financial meltdown of 2008, whose cast also includes Steve Carell, Ryan Gosling, Christian Bale and Brad Pitt. Pitt, with whom Magaro and Finn Wittrock share most of their scenes, also produced the film. The two were actually shot at widely different times (the release of “Carol” was held back for various reasons), but Magaro explained that one gets used to that. “You have to do that as an actor, because so much is out of your control,” he said in a recent Dallas interview. “So when it comes to the release, you try not to worry about it—you focus on the next thing. I like to try to keep busy, keep going.”

And one of the projects he went on to was “The Big Short”—a movie with an incredibly powerhouse cast. “I get accused of not seeming too excited about things,” Magaro admitted, “but secretly when I got this I was very excited. I didn’t scream at the top of my lungs. I do it a different way. I kind of coyly share it with people who are very close to me in my life.

“But the initial ecstasy, or ecstatic-ness—is that a word?—of being a part of such a cool project I try to put to the side and focus on the work, and show up and appear as a colleague and a peer to these guys. And Brad and all these other guys are there doing the same thing—they’re there to bring their best performance and support the script in any way they can and tell the best story possible. And they all of a sudden you’re collaborating with these guys whom you respect, and maybe afterwards you can think about how, on the day that you’re doing it, it’s just about telling the story. Most people, in any profession, even if you’re working with someone you respect, to actually do your job you have to put that out of mind and focus on the task at hand.

“It goes back to focusing on telling the story,” Magaro continued. “It can be nerve-wracking at times, especially in the month ahead of shooting, when you’re trying to crack the code and figure out what the story’s about and where you live in the story. That can be kind of frightening.

“I always get a little anxious on the first few days of shooting. It’s like the first-day-of-school feeling. You want to do your best and show up and deliver a strong performance, but you’re also thrown into a situation that’s somewhat unnatural, because you have to give yourself over and have ultimate trust in your director and fellow cast members, and a lot of times you don’t know them at all. But again, that’s about letting that go and focus on telling the story. Once you start doing that, hopefully things fall into place.”

The film, adapted by McKay and Charles Randolph from the non-fiction book by Michael Lewis, depicts, in a raucous, frenzied fashion, how a group of outliers in the financial world foresaw the bursting of the housing bubble and bet against the common belief that the skyrocketing market in securities based on it would continue. Magaro and Wittrock play small-time hedge-fund managers who get wind of the idea and persuade an erstwhile Wall Street player, played by Pitt, to help them get a seat at the table to profit from it. “How it all came about is a whole other story,” Magaro noted. “We’re showing a slice, a moment in time where it all came to a head, and a lot of people were affected.”

So one of the tasks the actor felt was to grapple with the financial complexities behind the scenario. “I felt very compelled to try to understand it as best as I could,” Magaro said. “It would be insulting the real Charlie [the real-life version of his character] if I didn’t do that. I’d say that was the most challenging part of doing this film—having some sort of grasp on the concept. I’d hardly say I’d mastered it, or that I’m a master of it. That would be insane to say,” he added with a chuckle. “But thankfully we had such good people around us that they gave us a pretty solid base.

“And once you start to dissect it,” he added, “it starts to make sense. A lot of these [financial] ideas are supposed to be confusing on purpose, to mislead people, and to say, ‘Oh, somebody else has my best interest at heart—just let them deal with it.’ But we had a great financial adviser… and he was extremely helpful. Charlie was very helpful, let me know what he was going through, gave me a lot of tips. I filled a notebook with notes on all this stuff. It was good, because coming in we had to do a lot of improv” (a McKay specialty, coming as he does from a sketch comedy background). “And without that base, without doing that homework, we would have been lost a sea. It really was vital that we all came in with some clue about what was going on and what these guys were going through.”

Asked about rehearsing with Wittrock, Magaro said, “No, Finn and I, we did a ‘chemistry test’—which is usually reserved for a male-female love interest, because all of our stuff is pretty much together. That was it. We had done ‘Unbroken’ before this, but we never met on that…two separate parts, and our pasts never crossed. So we did this chemistry read, and right away we had this rhythm going on, my anxiousness and neuroses combined with his eager neuroses sort of started to complement each other, and Adam responded to it. And then from that point on we didn’t really have any rehearsal time. We went off on our own, did our homework, and showed up that first day.”

So did Pitt. “I’d met him once before on ‘Unbroken’—so quickly. He showed up on set our first day of shooting, when we were doing those phone calls in the office. He stayed there all day off screen, in the corner improvising, coming up with hilarious ideas, cracking us up, really putting us at ease. It was a great first day, really took the edge off in a lot of ways.”

Magaro has since worked with Pitt on another film, “War Machine,” about General Stanley McChrystal’s time in Afghanistan. “It’s kind of a dark, comedic look at the policies that were implemented over there. Brad plays an off-the-wall, funny general, so it should be a very interesting film. I play one of his advisors…a few of us who are on his team are kind of the bubble that insulates him from what’s really going on.”

Another bubble, though not a financial one this time.