* Futures: Dow up 1 pt, S&P down 0.5 pt, Nasdaq up 4.75 pts
By Ryan Vlastelica
NEW YORK, Nov 7 (Reuters) - Salix Pharmaceuticals Ltd and mobile gaming company Zynga Inc were among the biggest movers of Friday's premarket session, with the companies holding the top two spots for active Nasdaq names.
Both saw heavy trading a day after their results, with Salix plummeting and Zynga advancing.
Salix sank 37 percent to $87.50, on track for its biggest one-day drop in its history. Volume was about 250,000 shares.
The stock has been under heavy pressure, with Friday set to be its sixth straight day of declines. The drop will wipe out much of the stock's gains for the year. Based on its Thursday closing price, the stock is up 54 percent in 2014.
The biotech company slashed its full-year forecast in results released late Thursday and said inventory for its key drugs had piled up. Sources familiar with the matter told Reuters that the inventory issue dissuaded Allergan Inc from acquiring the drugmaker.
On the upside, Zynga reported better-than-expected third-quarter results as it set its mobile gaming push in motion with releases such as "New Words with Friends."
The stock, which has lost almost 40 percent so far this year, rose 10 percent to $2.60 before the bell, on track for its biggest one-day jump since Jan. 31.
In the broader market, U.S. stock index futures were little changed on Friday, as investors held off bets ahead of a key jobs report that could indicate whether the market's record levels are justified by the economy's fundamentals.
Futures snapshot at 7:41 a.m.:
* S&P 500 e-minis were down 0.5 point, or 0.02 percent, with 127,938 contracts changing hands.
* Nasdaq 100 e-minis were up 4.75 points, or 0.11 percent, in volume of 21,185 contracts.
* Dow e-minis were up 1 point, or 0.01 percent, with 21,838 contracts changing hands. (Editing by Bernadette Baum)