I took a peek ... at the stock market graph for today, and it looks remarkably like a noisy square wave displayed on an oscilloscope. There were apparently four events that affected the markets in a roughly equal manner, and the timing was such that it resembles a square wave with a 50% duty cycle. I don't remember ever seeing something like this before!
If what I just said makes no sense to you, don't worry about it. It's sort of an electronics geek insider joke. I'm not making any comment about the market here, just noting a strange coincidence. I'm certain it means nothing of significance. :)