At the JPM Tech conference a few minutes ago, the CEO didn't exactly allay option-related concerns when he responded to a question: Did you guys backdate options: "We've established a committee to investigate this." Obviously, if they were no backdating taking place whatsoever, the CEO would have uncategorically said so (and the stock would have rocketed up!). However, his hedge answer about a committee led to the further selloff. Sorry dude.
Now a stop lost 10% ago, would probably be a good idea hope you are a buy and hold for 20 years type investor.