U.S. stocks closed lower Friday, with health care and tech stocks lagging, amid continued uncertainty ahead of next week's scheduled Brexit vote.
The Dow Jones industrial average lost 1.07 percent for the week, its worst since the one ended May 13. The S&P 500 lost 1.19 percent for the week and the Nasdaq composite fell 1.92 percent for the week.
"The market's down 1 percent (this week) so it isn't a good week, but there's a tension between event risk ... and profit trends that are starting to look a little better," said Jeremy Zirin, head CIO investment strategist at UBS Wealth Management Americas.
The Dow closed about 59 points lower after briefly falling 130 points. Apple and Merck had the greatest negative impact. Health care closed 1.1 percent lower to lead S&P 500 decliners, followed by a 0.9 percent fall in information technology.
Apple closed near session lows, off almost 2.3 percent after news intellectual property regulators in Beijing barred the tech company from selling models of the iPhone 6 and 6 Plus in the city, citing strong similarity to an existing Chinese phone. Apple said in a statement to CNBC it is appealing the ruling and that the phones are available for sale today in China.
The iShares PHLX Semiconductor ETF (SOXX) closed 0.85 percent lower for its first six-day losing streak since the one ended early January.
The Nasdaq composite and S&P 500 had their worst weeks since the one ended April 29. Telecommunications and utilities were the only gainers on the week.
The Dow transports closed more than half a percent higher Friday but fell 2.25 percent for the week, ending in correction territory, or more than 10 percent below its 52-week intraday high. The Russell 2000 lost more than 1.5 percent for the week, its worst since early April.
"I think there are a lot of distractions in the markets this week. Obviously a lot of focus on the (EU) referendum and interest around the very dovish sentiment expressed by the Federal Reserve," said David Kelly, chief global strategist at JP Morgan Funds. "I think that's got the market really confused here."
The U.K. vote on whether to leave the European Union is scheduled for next Thursday.