I glanced at Yahoo finance's home page on Friday, and noticed ZNGA was very prominently featured:
I figured using space that precious for a particular stock meant there was something very big going on. How much was Zynga up? 20%? 30%? 50%? I just had to check it out. Here's the daily chart. The stock was up eight pennies.
So there you go. You can put your microscope away now, having examined the action.