GameStop's stock price dropped six percent on Thursday following reports that new technology patented by Sony could eliminate the pre-owned games market.

The technology - which tags individual game copies with information about previous use - could potentially be used to restrict the use of a game to one machine or user account. This could mean bad news for the US retailer - a major player in the pre-owned market.
The market responded to the news with selloffs of GameStop shares, resulting in the retailer's share prices falling by $1.57 to $24.09.

Michael Pachter of Wedbush Securities moved to appease investors, claiming Sony would be unwise to implement the technology to its full potential. "Sony would be materially hurt if its console blocked used games and competitor consoles from Microsoft and Nintendo did not," Pachter wrote in a note to investors.

"We think the reaction is overblown," he continued. Indeed, SCEA CEO Jack Tretton is reportedly against moves to implement technology designed to block used games.

Elsewhere, an analyst for Janney Capital has noted a similar pattern in the lead up to the PS3's launch.