NEW YORK ( TheStreet) -- Intel ( INTC) was a big loser in premarket trading on Wednesday, tumbling 3.71% to $21.52 after the chip giant offered weak guidance when it reported its third-quarter results. The No. 1 chipmaker beat lowered expectations for its fourth quarter after market close on Tuesday, but cited continuing weak demand across the globe. For the fourth quarter, Intel expects sales of $13.6 billion, plus or minus $500 million. Analysts surveyed by Thomson Reuters were looking for sales of $13.74 billion, slightly above Intel's top-line view. The Santa Clara, Calif.-based firm expects a Non-GAAP gross margin between 57% and 58%, plus or minus a couple of percentage points. Intel was also the most active premarket Nasdaq stocks on share volume of 2,497,896. Security specialist Fortinet ( FTNT), which also reported its third-quarter results on Tuesday, was an even bigger loser, plunging 16.94% to $20.60 after the company cut its full-year forecast. The Sunnyvale, Calif.-based company reported in-line third-quarter results, but projected full-year revenue between $524 million and $528 million, below its prior forecast of $525 million to $530 million. Analysts were looking for revenue of $528.7 million. IBM ( IBM) was off 3.65% at $203.29 after missing Wall Street's top-line forecast in its third-quarter results on Wednesday. The tech bellwether edged past analysts' earnings forecast, but currency pressures weighed heavily on revenue. Excluding items, IBM earned $4.2 billion, or $3.62 a share, up from 10% from a profit of $3.28 a share in the prior year's quarter, and a penny ahead of the consensus view. But the Armonk, N.Y.-based firm reported revenue of $24.75 billion in the September-ended quarter, down from $26.16 billion in the same period last year, and below the analysts' estimate of $25.36 billion. Currency negatively impacted IBM's revenue by nearly $1 billion in the latest period. Cisco ( CSCO) was another premarket laggard, dipping 1.45% to $18.58, while Clearwire ( CLWR) slipped 1.35% to $2.20. Apple ( AAPL) shares were off 0.16% to $648.75. --Written by James Rogers in New York. Follow @jamesjrogers >To submit a news tip, send an email to: email@example.com.