Who's Responsible Now?

The stock market went up 500 points today (497.48) if you want to be exact. Now who's responsible for these gains? I mean every other day there're losses the media blames President Obama. Yesterday President Obama was on 60 minutes, I missed the interview myself, but I highly doubt that didn't have anything to do with the stock market gains. Every time the stock market went way up, who was responsible? Why don't you ask the media, they don't know either, but they sure know that it wasn't President Obama. And when the stock market declined, who did they blame? You guessed it, President Obama. So I ask, why is it that when there are gains President Obama isn't responsible, but when there are losses the media is quick to blame President Obama? Better yet why is the media doing a better, more extreme job than the republican party?