price should come down after euphoria dies down and remember the 3 day rule.
if price trends to pre-announcement level following ex date, good holiday sales should minimize retreat at least until the respective ER. I have not done enough DD yet to comment re sentiment but I'm at the table.
increased debt load means more interest deductions so lower earnings going forward, less tax dollars to govt again. Still the huge pop in stock despite higher leverage in debt going forward suggests investors believe Costco will continue to print money so good use of debt and they will pay it with ease - only now that they are much more leveraged to the economy and less $ cushion to fall back on if fiscal cliff does happen.. Overall, beta of this stock probably increased by quite a bit. Costco volatility will be much higher going forward.
My guess is that as the 10th and the cliffs approach, if the latter is of a negaitve leaning sentiment
the probability of a down day on the 11th is exponentially increased.
If the cliff looks like there may be some resolution without crushing middle america I still believe there will be a selloff although much less drastic.