Company earnings reports involve a lot of numbers. Unless you’re a student of Wall Street, or are following a company closely, it can be hard to decipher exactly what these numbers mean. Usually a good way to know how well a company did is to look at a stock price once the numbers are out. Last week we saw Google soar through the roof, going up over 20 percent upon beating estimates. Today, Yahoo’s stock is going up and down in after-hours trading — these swings are canceling each other out. This reflects Yahoo’s financial performance: decent, but nothing special.