Editor's Note: This article was originally published at 10:00 a.m. EDT on Real Money on May 28. To see Chris Laudani's latest commentary as it's published, sign up for a free trial of Real Money.NEW YORK ( TheStreet) -- Since bottoming out in July of last year, video game retailer GameStop ( GME) ( GME) has been on a tear as investors anticipate a slew of new gaming consoles this holiday season. The shares are up almost 100%. On Friday, the stock got whacked once investors realized that Microsoft's ( MSFT) recently-announced Xbox One could hurt the used game market. Any changes to the used game market would have a significant effect on GameStop's business model. Microsoft held a press event last Tuesday to announce the new Xbox One. While the announcement was long on hype and short on details, investors came to the conclusion that Xbox One could change the way used games are bought and sold. Presumably, Xbox One would allow consumers to trade used video games digitally after paying a fee to Microsoft. Customers would log in and pay for access codes, to activate old discs. While Microsoft has not confirmed the rumors, the gamer blogs lit up the Internet all weekend with angry rants about the possibility of having to pay a fee to trade a video game that you've already bought. After all, if you lend your car to a friend, the automaker doesn't get a commission on the transaction -- why should Microsoft? With the possibility of the used disc fee equal to the brand new disc, there would be little incentive to trade physical discs. The entire business would move to the Internet. Both Microsoft and Sony ( SNE) have danced around the issue by avoiding any explicit statements about the used market or how the new business model would work. (Although both say the used market will still exist.) One thing is clear. With gaming inevitably going digital, GameStop faces a very serious challenge to its business model. GameStop officials have said since the new gaming consoles are not backwards compatible, GameStop's business should stay healthy since buying and selling used games can continue for quite some time. After all, there are millions of old games out there. Many gamers like to browse through the used bins and pick up games they haven't played for 50% off. Used games account for 48% of GameStop's revenue.