Closing Bell: ISS Endorses SolarCity, Tesla Deal; U.S. Stocks Lose Ground

U.S. stocks fluctuated in the final hour of trading Friday to close lower as investors looked ahead to next week's presidential election. Another slump in crude oil also pressured markets. West Texas Intermediate closed with a weekly loss of nearly 10%, its worst week since mid-January. A weekly read on oil-drilling activity in the U.S. showed an increase in the number of active rigs. Whole Foods (WFM) was briefly halted in the early afternoon after volatile trading. The supermarket chain's shares spiked after reports emerged a major shareholder is pushing for changes, including a possible sale. SolarCity (SCTY) rallied after Institutional Shareholder Services endorsed Tesla's (TSLA) - Get Report plan to buy the solar company for more than $2 billion. The shareholder advisory firm said the deal was a necessary step for Tesla to become an "integrated sustainable energy company." TheStreet's Keris Lahiff reports from Wall Street.