Stocks ended up with a mixed finish on Wall Street Friday after another choppy day of trading, but major indexes still marked their third weekly gains in a row. The S&P 500 slipped 0.1% as sizable drops in several big tech companies outweighed gains in other sectors. The benchmark index had set its latest record high a day earlier. The Dow Jones Industrial Average rose 0.2% and the Nasdaq retreated 0.8%. Intel sank after the giant chipmaker’s revenue fell short of forecasts, and Snapchat’s parent company plunged after saying its ad sales are being hurt by a privacy crackdown on iPhones.