In the film "Trading Places", what is the name of Randolph and Mortimer Duke's brokerage firm?

The 1983 comedy film "Trading Places" was directed by John Landis, with a screenplay by Timothy Harris and Herschel Weingrod. Dan Aykroyd, Eddie Murphy, Ralph Bellamy, Don Ameche, Denholm Elliott, and Jamie Lee Curtis star. The film tells the story of an upper-class commodities broker (Aykroyd) and a poor street hustler (Murphy) whose lives cross when they are unwittingly made the subjects of an elaborate bet to test how each man will perform when their life circumstances are swapped.

Directly in the film, the brothers Randolph and Mortimer Duke own a commodities brokerage firm (Duke & Duke Commodity Brokers) in Philadelphia, Pennsylvania. Holding opposing views on the issue of nature versus nurture, they make a bet and agree to an experiment—switching the lives of two people on opposite sides of the social hierarchy. The results are observed. When they witness an encounter between their managing director—the well-mannered and educated Louis Winthorpe III, engaged to the Dukes' grandniece Penelope Witherspoon—and poor black street hustler Billy Ray Valentine, the Dukes decide to use Louis and Billy in their experiment. Valentine then finds himself arrested at Winthorpe's insistence after the well off manager assumes he is being robbed.

"Trading Places" was considered a box-office success, earning over $120.6 million worldwide. It also received generally positive reviews, with critics praising both the central cast and the film's revival of the screwball comedy genre.