The short answer is both.
The whole novel is wrought with cruel ironies. Brett casually having sex with almost everyone while Jake, the one she would probably be happiest with, just has to watch. They are constantly partying but not having a good time. They treat the most important things, like each other's feelings, in cavalier manner. They act wealthy when many of them are on the verge of bankruptcy. They are truly ridicilous.
They are outlandish, highly ironic characters, so in that sense they are satiric. The tragedy is found in how little exaggeration was needed the "lost generation."