Are you familiar with the concept of a Markov Chain? (If not, it's a simple tool that technically works better than randomly guessing for predicting stock movement.) I designed a very intense neural network meta-architecture, applied it, and the results were the same as if I'd used a basic Bayes model or Markov Chain. Which is a little humorous; I very much used a bulldozer to sweep the garage.
I used close minus open to determine up vs. down movment. Can't remember the lookback, but was predicting the immediate next day. Over the entire US market, a basic Markov-based model can predict the next day 52.5% of the time or something like that. (Given 1000+ stocks, you guess which direction all will go, 52.5% will be correct guesses.)
For what it's worth, I don't really know the details of the statistical tools. I do have a good grasp of train/test/validate sets, so I know what my results meant.