- "He and this Wolfsheim bought up a lot of side-street drug-stores here and in Chicago and sold grain alcohol over the counter." Gatsby was repeatedly rumored to be a bootlegger (someone who smuggles alcohol), and this seems to be true, since Gatsby doesn't deny Tom's accusation. There was a lot of money to be made by smuggling alcohol during Prohibition, but becoming a millionaire is a bit of a stretch; it seems to imply that Gatsby had some connections with the Mafia.
- "-he was a German spy during the war." There doesn't seem to be any legitimate source or support for this rumor, other than other rumors such as Gatsby being related to German aristocracy.
- “Well, they say he’s a nephew or a cousin of Kaiser Wilhelm’s. That’s where all his money comes from.” This is related to the German spy rumor - Kaiser Wilhelm was the political leader of Germany during World War 1.
- "Somebody told me they thought he killed a man once." This is probably the most frequently repeated rumor, after Gatsby being a bootlegger. In truth, Gatsby probably did kill someone once, since he served in the war. However, in terms of rumors, this seems only to be a sort of common ground; everyone can agree that a murder makes someone's past more unusual and interesting to the thrillseeking consumer, and this makes Gatsby's enigmatism exciting.
- “One time he killed a man who had found out that he was nephew to Von Hindenburg-" An interesting combination of some of the other rumors, and an indication that they aren't very reputable.