Lawrence Boyd tells Chuck that Roy Cohn was one of his mentors. Roy Cohn (a historical figure) really did mentor a number of young businessmen and politicians (most notably Donald Trump), but the premise of Cohn being a mentor to a fictional character most famously comes from the play Angels in America. Ben Shenkman (who plays Ira in Billions) appeared in the 2003 movie version of that play; Shenkman's character, Louis Ironson, calls Cohn "the polestar of human evil...like the worst human being who ever lived." Ten years before the movie, Shenkman also played Roy Cohn himself in an early New York University workshop version of the play.
When Orrin Bach (Glenn Fleshler) is speaking with Axe (Damian Lewis) about giving a deposition he says "In depos. I've seen things you wouldn't believe!" and Axe asks, "Attack ships on fire?" Bach responds, "Yes, the very best cases, gone forever, like tears in rain." Axe declares, "No replicant, no lawyer is gonna rattle me." This exchange is an obvious reference to the "tears in rain" monologue delivered by Roy Batty (Rutger Hauer) in Blade Runner.
When discussing the opposition their business is facing, Lara says to Mo, "I want my corners, Stringer." This is a reference to the critically acclaimed TV series, The Wire (2002.) In season 3, episode 6 (Homecoming), Avon Barksdale is facing a regime change in which his deputy, Stringer Bell, tries to cut out the need for having street corners to sell their drugs, insisting that they should supply dealers only and not engage in street dealing themselves as it often leads to turf wars and police attention. Avon, being a traditionalist, says to Stringer, "I ain't no suit-wearing business man like you, you know I'm just a gangster I suppose and I want my corners."
Axe meets with Sanford Bensinger (Richard Thomas) so it looks to the media like Axe is considering Bensinger's philanthropic Giving Oath. This oath is based in fact: in 2010, billionaires Warren Buffett and Melinda and Bill Gates founded the Giving Pledge, in which billionaires pledge to give more than half of their fortune to charity, instead of family, during their lifetimes or after their deaths. Buffett and the Gateses themselves became the first ones to join the pledge. As of October 2018, over 180 billionaires have signed the pledge, including Ted Turner, George Lucas and Melody Hobson, Michael Bloomberg, Mark Zuckerberg and Priscilla Chan, Diane von Furstenberg and Barry Diller, and Richard and Joan Branson.
When Wendy Rhoads is performing her psych evaluation of Elena Gabriel, Gabriel uses two phrases to describe outer space. She says "It's the undiscovered country" and "It's the final frontier." The Undiscovered Country is the subtitle for Star Trek VI: The Undiscovered Country (1991), while The Final Frontier is the subtitle for Star Trek V: The Final Frontier (1989).