Being one of the few to get caught up in the late 90’s stock market bubble (ha ha ha … Not) I learned a lot about reading stock charts.
At its core, charts are a graphical visualization of human behavior.
Like, for example, humans visiting a website.
I am forgetting some of the terminology after 10 years (yay!) but can still read a chart: Bollinger bands, day, weekly and month trendlines, gaps and filling gaps, retrenchments… All of this knowledge can be applied to your website statistics.
Not sure if this helps with SEO necessarily. More likely it tells you when to make a major push on your online marketing campaign because, for example, your highs and lows are converging to a single value and your traffic is going to gap down or up real-soon-now. And you would most likely want it to go UP!
And, finally, an idea for all you website/twitter analytics start-ups… try using some of the well known stock chart visualization techniques (Yahoo Finance is a really great site for examples). A great differentiator… and useful too :-)