Symbolism, Imagery, Allegory
Although it doesn't involve any Hangover-style hijinks, our heroes' trip to Las Vegas for the big subprime mortgage conference teaches them a lot about this hellish industry—and provides us readers with some tasty symbols to nibble on.
Right off the bat, we enter the Venetian to a wild scene: "a jangle of seemingly random effects designed to [...] to alter your perception of your chances and your money" (6.32). This is fairly easy to connect to the subprime mortgage bond market, as subprime bonds were explicitly designed to disorient outsiders into thinking that they're more valuable than they actually are.
In addition, Lewis notes that craps is the game of choice for bond traders. This is interesting, he says, because craps only "offered the illusion of control [...] and a surface complexity that masked its deeper idiocy" (6.32). Does that remind you of anything else? Hm? If you just said "CDOs," then you're completely right. As we see in the case of Howie Hubler, who tries to bet against the subprime market and accidentally bets for it, the subprime market is all about creating illusions.
Related to this is the screen in the casino which lists "the wheel's most recent spins" in order "to help gamblers [...] delude themselves" (6.24). This, as it happens, is an example of "recency bias," which is the mistaken belief that whatever is happening now will continue happening in the future. Again, this relates quite easily to the subprime market: banks thought that home prices would never fall, simply because they hadn't in recent memory.
Huh—looks like Las Vegas and Wall Street aren't so different after all.