Apprenticed Investor: Lose the News

Have you ever noticed how the stock market reacts differently to the same reported events?

Why is it that we sometimes sell off "in response to rising oil prices," but at other times the "market rallied, despite the rise in the price of crude"?

How come a selloff was caused by a suicide bombing in Iraq, but a week later, the markets shrugged off an even larger, deadlier bombing? Is it possible that the markets are responding to forces other than the latest headlines? ...