Because the stock market isn't really based in long-term hard reality. Volatility is all that is required for traders to make money. Dynamic = opportunity. You would have to look at exactly what the market is speculating on today to understand why it isn't tanking on the news that is coming out o the ME. Energy stocks? Companies that are insulated against or actually do better with inflation? Maybe there is hope that with the finding that the individual mandate for Obamacare is unconstitutional there will be some upside to business.
Who knows? The market can swing 200 or more points in a day without any significant change in fundamentals.
If Obamacare gets declared unconstitutional and is repealed, I think it will have the opposite effect on the market however.