NEW YORK ( TheStreet) -- Apple ( AAPL) was a big gainer in premarket trading on Thursday, as the consumer tech giant continues to grab the headlines. At the Consumer Electronics Show (CES) this week, Deutsche Telekom CEO John Legere told Reuters that a T-Mobile USA iPhone will be available within the next three to four months. Rumors also continue to swirl about a cheaper iPhone. Shares of Apple rose 2.39% to $529.44 before market open. The Cupertino, Calif.-based firm was also one of the most active premarket Nasdaq stocks on share volume of 467,735. Research In Motion ( RIMM), which is gearing up for its eagerly anticipated BlackBerry 10 launch later this month, was another big gainer. Shares of the embattled Canadian handset maker, which have plunged more than 25% over the last 12 months, rose 3.31% to $11.87 on share volume of 209,302 amid news reports that Verizon ( VZ), AT&T ( T) and T-Mobile will carry BlackBerry 10 smartphones. Chip design giant ARM ( ARMH) was another premarket winner, rising 2.75% to $41.11 on share volume of 170,495. Facebook ( FB) was a more modest gainer, rising 0.39% to $30.71, although the social networker was the most active premarket Nasdaq stock on share volume of 765,554. Microsoft ( MSFT), however, was a laggard before market open, slipping 0.56% to $26.55. The software maker was downgraded to equal weight by Morgan Stanley on Thursday. "MSFT is far too cheap, has multiple non PC drivers and an attractive 3.5% dividend yield. However, Win 8 is disappointing, the PC market will remain weak for awhile and margins are likely capped," wrote analyst Adam Holt, in a note. "As such, the stock is likely range-bound and we see better potential in names like Symantec ( SYMC) and Oracle ( ORCL )." --Written by James Rogers in New York. Follow @jamesjrogers >To submit a news tip, send an email to: firstname.lastname@example.org.