Today I want to write about a simple topic, yet one that few investors grasp: Big moves don’t just happen out of the blue. In the market, stocks (and the market itself, for that matter) take time to set up. And that means that the market’s crash during late-September and early October was entirely avoidable. Most investors, of course, will believe that such-and-such news item caused the crash, or they might comfort themselves by believing there was no way they could have avoided such a meltdown. I talk to many people in that camp every week. Really, though, it’s...