You might recall that in his last year in office, every time W opened his mouth, stocks plummeted also. Wall Street wants to hear a magical, sure-fire solution from the White House, and since there isn't one, every time the POTUS speaks, they freak out.
Unlike Dubya, at least President Obama is honestly seeking input and participation from everyone instead of just a small cadre of idealogue yes-men. In a politcally savvy, if very un-patriotic way, the GOP is doing the easy thing, distancing themself from any solution the Prez comes up with, so they can't be held accountable if it tanks. You'll note however that they aren't offering any alternatives beyond tax cuts.
Also unlike Dubya, Obama at least has the capacity to speak clearly and intelligently and to respond to questions from a diverse audience instead of a bunch of thoroughly-screened sycophants (and the occasional gay male escort posing as a journalist).
Bottom line: no one in government has any viable solutions to the economic free-fall we're currently experiencing. We can't tax-cut our way out of this, as the GOP would have us believe, nor can we deficit-spend our way out of this mess, as the Dems want to do.
Obama is a decent, intelligent, well-spoken president who inherited (from the last several presidents, not just W) a big, hairy, smelly, sabre-toothed, drooling monster of a problem. I'm not saying you should blindly follow him, I'm just saying you should give the guy a chance.