In The Great Gatsby, several rumors have been told about Gatsby. Some say he's a German spy, others that he graduated from Oxford. Some even say that he once killed a man. Fitzgerald reveals rumors rather than facts because he wants to maintain an air of mystery about this remarkable character.
Gatsby continues to spread false rumors about himself by claiming to have lived as a young rajah after the Great War. At the beginning of chapter 4, Nick recalls some of the rumors he hears about the identity and occupation of Jay Gatsby. Catalina repeats the rumor she heard that “he is the nephew or cousin of Kaiser Guillermo, and “that's where his money comes from. However, the subjects of the rumors in chapter 4 are the same as in chapter 3 where people speculate that Gatsby is a criminal or a spy.
In chapter 4 of The Great Gatsby, Jay Gatsby is rumored to be a German spy, a relative of the Kaiser, a smuggler, an Oxford man and a war hero, among other things. There are also rumors because a woman doesn't think Gatsby went to Oxford, even though he told her he did. In addition, there are rumors that he would be a spy for that Spanish people and that he would be a soldier within the U. These rumors reflect the mysterious nature of Gatsby's sudden rise to the top echelon of society and are attempts to explain his unusual behavior.
He says, in essence, that he doesn't want Nick to have a tainted vision or opinion of him based on stories (rumors) he has heard from several people. The most significant aspect of this question is why Fitzgerald presents the character of Gatsby through rumors. There are also rumors because a lady does not believe that Gatsby visited Oxford, even though he informed her that he did.