NEW YORK ( TheStreet) -- Polycom ( PLCM) was one of tech's biggest movers in premarket trading on Thursday as investors balked at the company's lowered first-quarter guidance. Shares of Polycom plunged $3.24, or 17.81%, to $14.95 before the market open. The Pleasanton, Calif.-based company reported its preliminary first-quarter results after market close on Wednesday, predicting revenue between $364 million and $370 million. In January, Polycom had forecast sales around $399 million. "We estimate that we grew quarterly revenues approximately 7 percent year-over-year, with each region recording increases," explained Andrew Miller, Polycom CEO, in a statement. "However, the growth rate was below our overall expectations, driven primarily by shortfalls in Asia Pacific and North America." Polycom, which is one of the Nasdaq's most active premarket stocks in terms of share volume, also forecast non-GAAP earnings between 21 cents and 23 cents a share. Analysts surveyed by Thomson Reuters are looking for earnings of 30 cents a share. Consumer tech giant Apple ( AAPL) and its embattled rival Research In Motion ( RIMM) are also among the most active premarket Nasdaq stocks. Apple shares, which hit a new all-time high of $632.31 earlier this week, gained $2.19, or 0.35%, to reach $626.50 before market open on Thursday. RIM, however, dipped a penny, or 0.08%, to $12.75. Shares of flash-memory specialist SanDisk ( SNDK) crept up in premarket trading on Thursday, after plunging in the aftermath of the company's weak first-quarter guidance earlier in the week. SanDisk gained 19 cents, or 0.43%, to reach $44.70 after closing down more than 11% on Wednesday. Zynga ( ZNGA), which announced the closing of its secondary offering earlier this week, gained 1 penny, or 0.08%, to reach $12.23. --Written by James Rogers in New York. >To follow the writer on Twitter, go to http://twitter.com/jamesjrogers. >To submit a news tip, send an email to: email@example.com. Check out our new tech blog, Tech Trends. Follow TheStreet Tech on your wireless devices.