When I was at Amazon I looked at a lot of graphs. Graphs of hits, graphs of cpu, graphs of all sorts of shit. Graphs are great, I loves them. However, the problem is that if you aren't in a habit of looking at the relevant graphs every day, and then something happens, you're faced with the problem of deciding what's normal. It is so easy to find patterns, especially if you have a good reason to think something important is happening (either for a good or bad reason).
I'm reminded of all this when I happen on a GeoCities-tastic page like this: http://www.trading-naked.com/headandshouldersREVERSE.htm I am no stock expert but I'm willing to bet the patterns he is using are tenuous at best. Then again, maybe the market wouldn't work without people like him?