I remember reading a piece on earnings analysts, and they found that some analysts had skill at forecasting earnings and some at predicting stocks returns. But they weren't the same people. No better example than today, where many banks missed badly (KeyCorp, WaMu, Wachovia, Regions), but they rallied strongly! It wasn't that they lost less than expected, they actually lost more than expected, and still rallied. Thus, anyone good at fundamentals got burned; those who were wrong, were right, and vice versa.
The real point there is that if you are a fundamental investor, your horizon is not a day. It's several quarters, if not years.
It reminds me of this economist I worked for. He was telling some senior guy we should buy grain commodities, because there was going to be a drought (economists like geeky stuff like weather). It turned out there were floods. Sign error. But floods kill crops just like a drought! So wheat went up.