Tech stocks: GameStop tumbles, Microsoft surges

Shares of GameStop plunged 5% in morning trading on Tuesday after Wal-Mart announced it was entering a prime space for the video game chain: used games.

Wal-Mart unveiled its new used games service, which will allow consumers to trade in older video games and apply it to any item purchased at Wal-Mart or Sam's Club. The program kicks off March 26.

"Our strategy is to pay more for used games, sell new and used games for less, and give our customers the flexibility to spend their money how they want," said Justin Williamson, director of entertainment at Wal-Mart, in a blog post.

The used games industry has been dominated by GameStop, which makes a healthy chunk of its revenue off trade-ins. Wal-Mart isn't the only retailer to wade into the used games market. Both Amazon and Best Buy host similar services.

Sterne Agee analyst Arvind Bhatia estimates 43% of Gamestop's gross profit dollars come from their used games business.

Meanwhile, Microsoft stock is up 4.2% following reports the company plans on making its Office software available for Apple's iPad.

According to The Verge, Microsoft plans to host an event next week where it will unveil a version of its suite of Office apps for the Apple tablet. The report says the interface and features will be similar to the Office app for iPhone.

Also, Hewlett-Packard shares are up nearly 2% after Barclay's upgraded the personal computer maker's stock to "overweight." As CNBC reports, Barclay's thinks HP can improve how it implements its tech services and gain share in its x86 enterprise server business.

Follow Brett Molina on Twitter: @bam923.