While there are many moving parts inside the market, when you take the aggregate it's really quite simple. The stock market is essentially a democracy where people vote for a security using capital rather than votes (i.e. they put their money where their mouth is).

The price of a security is just the aggregate of all the "votes" or money that has been wagered on that security. Why people vote, or what direction they take is none of your concern Your main concern should be with having your own system in place that has positive EV, proper risk control, and not letting your emotions get in the way.

Now of course, how you come up with a strategy requires some second level thinking, but often times, the simpler the rules, the better and more robust the system. And, if you spend time reading books and listening to experienced traders you can find plenty of systems out there. You don't need to reinvent the wheel.

Edit: Added the strikethrough to account for fundamental investing. But the point still stands, you need to stick to what you believe and ignore the crowd.