The film was conceived as a vehicle for Gene Wilder and Richard Pryor. When Pryor dropped out and Eddie Murphy came on-board, he made a motion to get Wilder replaced because he didn't want people to think he was just trying to be another Pryor.
In 2010, as part of the Wall Street Transparency and Accountability Act, which was to regulate financial markets, a rule was included which barred anyone from using secret inside information to corner markets, similar to what the Duke brothers tried to do in the movie. Since the movie inspired this rule, it has since become known as the Eddie Murphy Rule.
Several funny moments in the film came about by accident. The scene where Mortimer Duke (Don Ameche) is trying to catch the money clip, and having trouble, wasn't supposed to happen that way, but both kept going with it, and not breaking character, so it was kept in the movie. Ophelia's "Swedish" disguise came about because Jamie Lee Curtis couldn't do the correct Austrian accent.
Eddie Murphy later admitted that while on the floor of the commodities exchange in the final scene, he only followed the script, he had no idea what was going on, as he found commodities trading incredibly confusing.
The story about the Dukes' cornering of the orange juice market was probably inspired by the "Silver Thursday" market crash of March 27, 1980, during which, the Hunt brothers of Texas tried to corner the silver market, and subsequently failed to meet a one hundred million dollar margin call.
In the scene with Valentine in the restaurant, with Winthorpe standing outside in the rain, Valentine is asked for his opinion about wheat. At that moment the entire room stops speaking and leans into hear his advice. This is a reference to a series of 1980s commercials for the brokerage firm, E.F. Hutton. The tagline was, "When E.F. Hutton talks, people listen."
DIRECTOR TRADEMARK (John Landis): (breaking the Fourth Wall): Eddie Murphy looks directly at the camera, as he is being taken away in a police car. When Randolph Duke explains to him what a B.L.T. is., he looks right into the camera as if to say, "These guys must think I'm a complete idiot."
In the opening montage of Philadelphia there is a shot of the Rocky statue erected in Rocky III (1982), that was released the previous year, and was still sitting at the top of the steps in front of the Philadelphia Museum of Art. The statue now resides at the base of the museum steps.
The exterior shots of Louis Winthorpe's house are of a house on a very affluent street in Philadelphia. The wreath on the door was replaced, when the producers wanted something bigger and better. They borrowed a handmade wreath from a house across the street.
Was filmed immediately after the Twilight Zone: The Movie (1983) accident, when Vic Morrow and two child actors were killed when a helicopter crashed during production. John Landis was later tried and acquitted of manslaughter, the first time in history that a Hollywood director was charged for a death which had occurred on-set.
When Winthorpe and Valentine arrive at the World Trade Center, Winthorpe tells Valentine "In this building, it's either kill or be killed". This line was removed from some television broadcasts after 2001, out of respect for the victims of the September 11 attacks.
The Screenwriters hung out with drunk traders for research. "The traders I met and hung out with here in Los Angeles, because it was three hours behind New York City, had their happy hours very early in the day," Herschel Weingrod explained to National Public Radio. "You can imagine what they were like by, maybe, 2 p.m."
DIRECTOR TRADEMARK (John Landis): (police): Frank Oz has a cameo as a police officer who is checking in Winthorpe's property when he gets arrested. In The Blues Brothers (1980), he played an officer who is giving Jake Blues his property back to him. Oz later reprised the role in Blues Brothers 2000 (1998).
The World Trade Center's commodity exchange, Comex, was used for the trading scenes, and real traders performed alongside professional extras. As reported in studio production notes, the shoot at Comex was initially planned for a weekday, but the appearance of Dan Aykroyd and Eddie Murphy on the set, distracted business activities, and six billion dollars of trading was halted. The shoot was rescheduled for a weekend.
Prior to this film, John Landis didn't know who Eddie Murphy was. "48 Hrs. (1982) hadn't come out yet, but they'd previewed it, and Eddie Murphy had previewed very well, and they thought, 'Ah this kid's going to be a star,'" Landis recalled of his discussions with Paramount Pictures. "So they said, 'What do you think about Eddie Murphy playing the Billy Ray Valentine part?', and I of course said, 'Who's Eddie Murphy?'"
A scene in the movie, not included in the theatrical cut, but seen frequently when the movie is shown on television (presumably to fill a longer time slot with commercials) occurs after Clarence Beeks (Paul Gleason) talks to the Dukes via telephone, and Billy Ray (Eddie Murphy) eavesdrops on their scheme. In the original cut, Beeks goes from the phone booth to the Amtrak train platform, holding the briefcase with the crop report. In the added scene we see Beeks procure the reports from a secured vault where he drugs a security guard and opens a safe deposit box.
This was Don Ameche's first film since Suppose They Gave a War and Nobody Came? (1970). He had been doing television guest appearances. This movie jump started his return to theatrical films, including an Academy Award for Best Supporting Actor for Cocoon.
Winthorpe's watch, a "Rouchefoucauld", is named after French writer François de La Rochefoucauld. Winthorpe names six cities, with the intention that the watch tells six different time zones, which is not the case. Monte Carlo, Paris, Rome, and Gstaad all share the same time zone, so the watch tells only three.
The Dukes' starting salary for Valentine (eighty thousand dollars) is a little over one hundred ninety-four thousand dollars, when adjusted for inflation in 2016. Their five dollar "Christmas Bonus" for Ezra is twelve dollars and fourteen cents in 2016 dollars.
The theme of rich men taking in a bum and passing him off as an aristocrat is reminiscent of the George Bernard Shaw play Pygmalion, and also includes specific elements of Hoi Polloi (1935), a previous American film parody of the same play. The theme of a rich and poor person exchanging positions in life comes from the Mark Twain novel The Prince and the Pauper.
The idea for the film was inspired by a tennis game. "There were these two brothers who were both doctors who I would play tennis with on a fairly regular basis, and they were incredibly irritating to play with because they had a major sibling rivalry going, all the time about everything," Screenwriter Timothy Harris explained. He presented the idea of brothers arguing the "nature versus nurture" debate to his writing partner, Herschel Weingrod, and the two went to work.
DIRECTOR TRADEMARK (John Landis): (breaking the fourth wall): When the Dukes explain to Billy Ray what bacon is, he looks directly into the camera as if to say, "These guys must think I'm a complete idiot."
When William (Billy Ray) is dining in the fancy restaurant with Mortimer, Randolph at a table full of other wealthy customers, while Louis stands in the rain and watches him through the window, the music playing in the background is the same as that was used in "The Blues Brothers", when Jake and Elwood are dining in the fancy restaurant, and trying to get "Mr. Fabulous" to rejoin the band.
The house used in the film is not the Rosenbach Museum and Library, but is a private house two doors west. Both houses, however, were built at the same time, and originally had identical floor plans. During the filming of the movie, DeLancey Place was closed for a few days. Denholm Elliott was the only actor in the film to visit the Rosenbach. The staff of the museum were all given Pennsylvania State Film Commission t-shirts.
The shooting schedule included fifteen days in Philadelphia for exterior scenes, and for the interior of the Duke & Duke Christmas party, which was located at the Fidelity Bank Building on Broad Street. Other locations in Philadelphia, included Rittenhouse Square, Independence Hall, a street of restored townhouses in Center City for the exteriors of "Louis Winthorpe III's" house, and the Philadelphia Mint for the exteriors of the police station. New York City locations, which were shot in January and February 1983, included the Park Avenue Armory for the Heritage Club, the Duke & Duke office interiors, and an Upper East Side residence, which was used for the interiors of Winthorpe's house. The apartment of Ophelia, Barney's Pawn Shop, and the interiors of the police station, were all shot in New York City, even though they had Philadelphia locations in the context of the film.
Randolph Duke has a picture of Ronald Reagan on his side of the Dukes' shared desk, while Mortimer has a picture of Richard Nixon. Bryan Clark who portrayed Stock Exchange Official #2 has often played former President Ronald Reagan.
During the processing of Louis Winthorpe III's arrest, an officer played by Frank Oz inventories Louis's personal property. Frank Oz also played the Illinois Department of Corrections officer at Joliet prison who inventories and returns Joliet Jake Blues' personal property upon his release during The Blues Brothers also starring Aykroyd as Elwood Blues.
Tony Sherer, who plays Winthorpe's friend Phillip (the one who says they "need a fourth for squash"), ended up teaching Drama and English at the same private grade school attended by Bryce Dallas Howard.
The trivia items below may give away important plot points.
Ralph Bellamy (Randolph) and Don Ameche (Mortimer) make cameo appearances in Coming to America (1988); the two are homeless and Prince Akeem (Eddie Murphy) gives them a large amount of money to get them back off the streets.
Don Ameche's strong religious convictions made him uncomfortable with swearing. This proved to be a problem for the scene at the end of the movie, where he had to shout out "Fuck him!" to a group of Wall Street executives. When he did act out the scene, it had to be done in one take, because Ameche refused to do a second one.
The main titles are accompanied by the overture to "The Marriage of Figaro" by Wolfgang Amadeus Mozart, and in an early scene, as Louis is leaving his office he whistles the beginning of the aria "Se vuol ballare" from the opera. In that aria, Figaro declares his plan to turn the tables on his master, just as Louis and Billy Ray will eventually outwit the Duke brothers.
Winthorpe and Valentine conduct what's known as "short selling", selling stock (or commodities) that one doesn't own, and then repurchasing the security at a lower price. It's the same principle as "buy low, sell high", just with the actions performed in reverse order. This is available to most clients, in the sense that they borrow the security from the holdings of their brokerage houses. It doesn't seem like Winthorpe and Valentine have a house from which to borrow their F.C.O.J. contracts, but Winthorpe appears to have had the guts to short sell on the fly, knowing the consequences of a mistake. Winthorpe was trading on a cash basis, using cash collateral, which is why Coleman and Ophelia gave the two traders all their cash in the train station.
The Duke brothers' manipulation of Louis and Billy Ray's fates is similar to God and Satan's bet in the Book of Job in the Old Testament. God presents Job as a good example of a righteous man, but Satan says he is only faithful to God, because God has rewarded him. To test his faith, God agrees to let Satan take away all of his friends and riches. The climax, in which Louis and Billy Ray take their revenge by using false information to trick the brothers into losing money at the stock exchange, is not unlike how Edmond Dantès take his revenge on Danglars in The Count of Monte Cristo by Alexandre Dumas.