‘Billions’ actor Kelly AuCoin on the ‘unexpected’ season finale, breaking his rib on set 

Kelly AuCoin plays "Dollar" Bill Stearn in Showtime's "Billions." 
Kelly AuCoin plays "Dollar" Bill Stearn in Showtime’s "Billions."  Photo Credit: Netflix/Atsushi Nishijima

Kelly AuCoin’s most rewarding "Billions" scene this season was also his most painful. 

The actor — who plays Axe Capital’s "Dollar" Bill Stearn in Showtime’s NYC-set drama — had a season 4 arc that saw him get into the boxing ring against Mafee (Dan Soder). The pair threw choreographed punches at one another while hundreds of extras cheered, but one of those jabs ended up actually breaking AuCoin’s rib. Consider it method acting, combined with some serious dedication. 

The actor, who’s lived in Brooklyn for 22 years ("the longest I’ve ever lived in one place in my life"), chatted with amNewYork ahead of the season’s big finale to break down that fight scene, his character’s involvement with Bonnie (Sarah Stiles) and more. 

What should fans expect heading into the "Billions" season 4 finale? 

Kelly AuCoin is "Dollar" Bill Stearn and Sarah Stiles is Bonnie Barella in "Billions."
Kelly AuCoin is "Dollar" Bill Stearn and Sarah Stiles is Bonnie Barella in "Billions." Photo Credit: Jeff Neumann

Expect the unexpected. I know that’s such an annoying cliché, but it’s true. You’re not going to guess what happens. It’s going to catch you off guard. That’s all I can say. One of the things I love about the show is I never know what’s going to happen and every time I try to guess, I’m always wrong. Theirs is always 10 times better, anyway.

You’ve had the chance to share more screentime this season with Sarah Stiles, who plays Bonnie. I’m a little skeptical of their involvement — should I be? 

[Laughs] Yeah, that’s interesting. Dollar Bill’s gotta be a little bit thrown. It was fun to see him a bit thrown. He’s so good at playing these games and I think he’s surprised by Bonnie. He saw Bonnie as formidable, but wasn’t really expecting anyone to pull anything over on him. There was sort of this yo-yo thing happening between them. Yes, she played him. But, yes, she was interested. So, he wasn’t wrong. He did feel the vibe but he was wrong in that she got information him and doesn’t quite know what to think. He’s not used to being off balance like that. 

Where is this relationship going? 

That is a very good question and is one that I have totally asked the showrunners as well. I honestly don’t know where we’re going to go with this. We are kept in the dark as much as everybody else.

Sarah and I hit it off when she first joined. We had chemistry right away, so it’s fun to work with her and we’ve become friends and hang out offset as well. 

What was it like filming your big boxing match scene this season? 

Well, I broke my rib on the first take on the first show of the day. So, it was more strenuous than I thought it would be. I’m perfectly mobile. Fortunately, with the adrenaline rush, I didn’t really feel the pain until the next day. Then I had the better part of the next two weeks off so that allowed time to get better. We shot over a 12-hour day. If we hadn’t been able to finish I don’t know what the production would have done. We couldn’t rent that room again, with 300 extras. I’m glad I was able to keep going. 

Overall, it was really just stupid fun. We rehearsed it and choreographed it about a month beforehand. We just had fun with it. 

And you had some help from Deontay Wilder (WBC Heavyweight Champion). 

Meeting Deontay Wilder! I’m not a huge boxing fan, but I certainly know who he is and it was very fun to come out on set and meet him. I will say this — there’s nothing quite like it. I know I’m not Dollar Bill, and people were chanting Dollar Bill, but there’s something pretty awesome about that moment. We’ve all seen these movies, like "Rocky," and being able to walk through a crowd while people are chanting "Dollar Bill! Dollar Bill!" and have the actual heavyweight champion of the world help you get into the ring, lift up the ropes, was a pretty heavy experience. 

Some fans and critics compared Dollar Bill’s fight arc (which ended with a draw) can be symbolic for the journey of "Billions" in a whole. Have you thought about this? 

I’ve never thought about that before. But, I could see it in far as you have old school versus new school fighting it out. One of us represents the old way of doing something. I’m not an expert on the deeper meaning though! 

Aside from "Billions," you’re currently starring in Manhattan Theatre Club’s "Long Lost." How has it been juggling these projects?

Well, I love being on stage. It’s my first love. It’s why I moved to New York. To work at the Manhattan Theatre Club where I’ve worked before has been incredibly welcoming, as is the theater world I’d have to say … The show is incredibly relatable, with struggling relationships and people not always at their best.