Marcus Halberstam from American Psycho works with BAteman and Own. They are all rich, in tehir twenties, and work on wall STreet. Halberstam is who Owen believes Bateman is..mainly because he wants information on an account that Halberstam knows about. This identity mistake is actually what initially saves BAteman because everyone thinks it was the real Halberstam who was having dinner with Owen when he disappeared.
