forget the math and logic; if citi went tits up at this point it would throw a wrench into the financial system as large as lehman bros. the govt will go to great lengths at this point to avoid a catastrophe of those proportions again. the govt is on the side of citi. your betting against benny and the boys, timmie et al.
i wouldn't do that myself. they just have to much to gain in every sense of the word to let that happen. numbers be damned. to say nothing of the fact AIG makes citi look like gold bullion. so...keep shorting. best of luck to you.