Thursday's early afternoon trade: stocks dip as Facebook, election worries weigh

US stocks reversed course to trade lower on Thursday as concerns over the tightening race for the White House and a fall in Facebook's shares weighed on sentiment.
Facebook fell as much as 5.9 percent to a more than three-month low of $119.61 after the social media giant warned that revenue growth would slow this quarter. The stock was the biggest drag on the S&P and the Nasdaq.
The S&P was on track to close lower for an eight day, the index's longest losing streak since the financial crisis of 2008.
Investors have been unnerved by the signs that the US presidential race between Democrat Hillary Clinton and Republican Donald Trump was tightening just days before the vote.
While some polls put Trump ahead on Tuesday, an average of polls compiled by the RealClearPolitics website showed Clinton retaining a slight lead. A Reuters/Ipsos daily tracking poll released late on Wednesday showed Clinton ahead by 6 percentage points among likely voters.
"Stocks are going to be more volatile and will move sideways with a slight downward bias until next week because the election seem incredibly tight and there's a lack of political visibility," said John Brady, managing director at R.J. O'Brien & Associates in Chicago.
The CBOE Volatility Index, a gauge of near-term investor anxiety, was up about 7.8 percent at 20.84, its highest level in more than four months.
In another negative technical sign for the market, the combined number of 52-week lows on the NYSE and the Nasdaq significantly outpaced the number of new highs.
At 12:49 p.m. ET (1649 GMT) the Dow Jones industrial average was down 17.1 points, or 0.1 percent, at 17,942.54.
The S&P 500 was down 6.45 points, or 0.31 percent, at 2,091.49.
The Nasdaq Composite was down 31.24 points, or 0.61 percent, at 5,074.33.