Earnings season is here again, that time of the quarter when thousands of companies tell investors how they performed during the prior three months and, more importantly, how they believe they’ll fare in the three-to-nine months to come. These four periods each year—generally the latter half of January, April, July and October—have become vital for investors, as stocks can make big moves in the blink of an eye. In the old days (by old, I’m talking about 10 years ago), earnings reports were noteworthy, but not all-important. Back then, analysts would often get the “wink, wink, nudge, nudge” from...