The most you can lose on any stock (assuming you don't use leverage) is 100% of your money. But when you pick a company...
In the most recent trading session, Groupon (GRPN) closed at $15.30, indicating a +1.73% shift from the previous trading day.
In the most recent trading session, Groupon (GRPN) closed at $15.04, indicating a +1.01% shift from the previous trading day.