Graph Analysis

So why don't more of you /prog/rammers write software that trades stocks or currency? I've decided I'm going to try trading currency, and I set up a scraper to put exchange rates into a data base every 5 minutes.

Maybe I'll find out otherwise when I start the software in a few days when I have actual data, but isn't it just graph analysis?

And if it isn't, couldn't you just set a genetic algorithm on the market or something?

Let me get this straight op. You want to buy stocks or whatever and then when your stocks or whatever increases marginally you sell it and make money off the difference and repeat?

Is this your strategy?