Markets Moving Monday

Some years back, I made a call that the markets would rise sharply at the start of a particular week. Instead, they took a tumble. A bit later, I was certain the markets were going to sink on a particular Monday. They actually rose over a hundred points. I figured the only thing I could pretty much count on was that the markets would move. I could not predict up or down- but the markets were certainly going to go one way or the other on a particular Monday. That day the market actually closed unchanged.