Plot

A group of wealthy boys in Los Angeles during the early 1980s establish a 'get-rich-quick' scam that turns deadly.

Led by their fellow prep school friend Joe Hunt (Ansel Elgort), a group of wealthy young men in 1980s Los Angeles come up with a plan to get-rich-quick with a Ponzi scheme. The plan ends badly for all involved when Hunt and friend Tim Pitt (Bokeem Woodbine) end up murdering investor and con man Ron Levin (Kevin Spacey).

Dean Karny (Taron Egerton) is a salesman, who used to study with Joe back in High school. They both run into each other at a random hotel in Jan 1983 (6 years after high school), each with their clients. Dean was trying to sell a luxury car to his client, when he saw Joe Hunt across the room trying to sell a financial scheme to his client. Joe was always the smartest guy in the room, wearing the cheapest suit. Dean comes from middle class but was sent by his parents to the most elite prep school (The Harvard School for Boys), where he met all his rich friends, including Joe (who was a scholarship kid with no friends). Dean learned that the only trick was to fake it till you make it. Dean learned to use his wits and charms to hang out with sons of movies stars and actual royalty.

Dean proposes a partnership with Joe to start an investment fund. Joe Hunt would be the brains and Dean would bring in the money through his connections. Dean asks Joe to come to Charlie Bottoms (Thomas Cocquerel) birthday party (at the hottest club in town) in the hope to get investors so that Joe could start his own shop. At the party Dean introduces Joe to Scott Biltmore (Ryan Rottman) and Kyle Biltmore (Jeremy Irvine), twins and Harvard graduates and good friends with Charlie. All the 3 boys are filthy rich. Joe fluffs his first pitch about investing in Gold (Joe's pitch is too technical and gets buried in the party mood at the club) and goes home depressed. Dean sold a Covette on behalf of Kyle and owes him $10,000.

That night he reads an article on Steve Jobs (who made computer technology "Simple") and decides to make investing "Simple". He launches the BBC or Billionaire Boys Club with Dean as his partner. Dean tells Joe that Kyle has given $ 10,000 to Joe to invest, which Joe invests with modest positive returns, just as the market tanks. This wipes out 50% of Kyle's money. Dean tells Joe that Kyle doesn't actually know that Dean gave Joe the $10,000 which was owed to Kyle as payment for his car, which Dean sold on his behalf. Which means Kyle never knew that Joe invested the money on his behalf. At the next pitch, Joe lies and tells Kyle that $5,000 is the profit on his investment (not the leftover amount). He then pitches BBC to the entire group, who buy in thinking of a 50% profit margin in 3 weeks. Joe plays to the deep embedded anxiety in the young sons to show their fathers that even they could put the family assets to work and contribute to the family wealth.

Dean introduces Joe to Ron Levin (Kevin Spacey), a Beverly Hills high roller. Ron made his money in Wall Street before moving to the west. Ron likes Joe from the get-go and teaches him that the perception of reality is bigger than the reality itself. Ron knows Joe is a hustler just like him. Ron introduces Joe to Andy Warhol (Cary Elwes). Joe uses Andy's student Sydney Evans (Emma Roberts) to try and get Andy as an investor in BBC.

Using the money from Charlie and Biltmore boys, Joe & Dean import blacklisted Beamers into USA. They get $10,000 cars into USA for $15,000 landed and sell them for $80,000. On still refuses to invest and says that Joe's game is still too small for him. Charlie and Biltmore then become the salespeople for BBC, getting in their father's friends to invest. Ron comes through eventually and hands over $ 4 million to Joe to invest. This brings in more people to put up their retirement funds into BBC. Joe is disturbed at the moral implications, but Dean pushes him to keep going ahead with his Ponzi scheme.

The next gambit is for the BBC to buy an energy company with $ 3 million in debt, who is trying to figure out a process to liquefy coal to use it as natural gas. The trick is buying the company and an abandoned gold mine, to convince the markets that they have cracked the process. Joe makes the pitch to Cogenco (the energy company's investors) so that they can get their hands on $250 million in value for a fraction of the money. The deal was to be financed using Ron's money.

Delirious with impending success, Joe & Dean rent a luxurious apartment in Beverly hills. Joe & Sydney hook up. They throw a party where they meet Izzy - Reza Eslaminia (Barney Harris), who is the son of a Persian despot and hates his dad. The next day Joe realizes that Ron conned him. Ron never had the money and had used his relationship with Joe to secure a $ 1.5 million loan for himself. The penny drops for Joe as without Ron's money, the Cogenco deal is dead.

That night Joe confronts Ron at his house, with his bodyguard Tim (Bokeem Woodbine). When Ron insults Tim, he shoots him dead. Its July 1984 when Tim and Joe pour acid over Ron's body outside LA. To salvage the Cogenco deal, the group reaches out to Izzy. Izzy tells them that his father's locker in LA has $5 million in diamonds. When Izzy's dad comes to know, he attacks Dean and Dean ends up strangling him.

The next morning, Joe heads to the bank to get access to the locker and is arrested at the bank for Ron Levin's murder. Dean sells Joe in front of the cops. Dean turned witness for the prosecution. Joe was sentenced to life in prison for murder of Ron.