(CBS Local)– Kelly AuCoin almost passed up the opportunity to be on “Billions.”

Aucoin, who plays Axe Capital’s Dollar Bill Stern, had to be convinced by his friend and actor Michael Kelly to take the part. Let’s just say the decision ended up working out for him.

“I auditioned for one role initially and didn’t get that, but they called me back for this character called Dollar Bill,” said AuCoin in an interview with CBS Local. “This would’ve been such a huge mistake, but I initially said I don’t want to do that. It didn’t even say it was a potential recur, it was a one-off. Over the weekend I thought about it and I was like his name is Dollar Bill and he’s the cheapest millionaire in America, there’s something to this guy.”

AuCoin says it would’ve been the worst decision of his career if he passed up this past. Season four of “Billions” returns Sunday and Dollar Bill will be a series regular for the first time. His character has come a long way since the first season.

“I didn’t do a ton early on, but even in those small little sections it was a blast,” said AuCoin. “It was very fun to play and the group gets along so well. We started building this family from day one.”

In addition to his work on “Billions”, AuCoin has done a Broadway play with Denzel Washington, been directed by Steven Spielberg and even worked with Robert De Niro in “Wizard Of Lies.” The De Niro experience will always hold a special place in AuCoin’s heart.

“That was off the hook! Barry Levinson is an awesome director. I handcuffed Rober De Niro and he didn’t kill me,” said AuCoin. “He had a bunch of big coats on and I couldn’t get his arms together, so I never actually successfully did it. We had to fake it and there was one time when De Niro was like ‘you got it there?'”

Season four of “Billions” premieres Sunday at 9pm EST/PST.