It's still early in the session, but the Dow is actually up about 50 points, which would indicate a less-than-panicky reaction to the government shutdown. For what it's worth, conventional wisdom on Wall Street is that a deal will be hammered out before too much damage is done - say, by the end of the week. But obviously nobody knows how long the few dozen Republican radicals in the House will keep John Boehner hostage. That's what this comes down to (the full House would likely sign off on a continuing resolution that would end the nonsense). A new Quinnipiac poll shows minimal national support for keeping the government closed in order to leverage a deal on the health care law. Keep in mind there are other factors impacting the market: This is the first day of a new quarter and that often brings out buyers, shutdown or no shutdown.
*Update: Dow gains 62 points on the day.