Bad news can be good news for an enterprising investor with a longer time horizon than the market's immediate reaction. About once every 90 days, publicly traded companies have to face their shareholders and let them know how their businesses have performed over the past quarter. Those earnings releases often bring with them all sorts of news that can move the market. Sometimes that news is bad, which can knock a company's stock down. Yet that can provide an opportunity for investors to buy shares at a barg ...