US STOCKS-Futures slump as selling pressure continues
* Netflix tumbles in premarket after quarterly results
* Initial jobless claims data on tap
* Futures off: Dow 180 pts, S&P 24.25 pts, Nasdaq 56.25 pts
By Chuck Mikolajczak
NEW YORK, Oct 16 (Reuters) - U.S. stock index futures tumbled on Thursday, after the S&P 500 closed at its lowest in six months, amid concerns about weak global demand and its potential impact on the U.S. economy and businesses.
* The S&P 500 and Nasdaq briefly fell into negative territory for the year on Wednesday as the S&P tumbled more than 3 percent to a session low, before rallying late in the session. The decline was also spurred by worries over the potential spread of the deadly Ebola virus and its possible impact on the travel industry.
* The benchmark S&P index has dropped in 6 of the past 8 sessions and is down 7.4 percent from a record closing high Sept. 18. The CBOE Volatility index is up 118 percent since the S&P record, and closed Wednesday at its highest since June 2012.
* Earnings reports did little to stem the equity rout. Netflix shares shares plunged 25.9 percent to $332.40 in premarket after it reported quarterly results and said it signed up fewer video-streaming subscribers than forecast for the quarter.
* S&P 500 companies expected to report earnings on Thursday include Goldman Sachs and Google. Continuación...