A drop in Apple dragged down all three major U.S. stock indexes on Friday even as investors remained wary of global economic growth worries and an impending referendum on Britain's European Union membership.
Britain will vote on June 23, an event that has weaved in uncertainty across the globe, battering stocks and bond yields for the past week and spiking the demand for safe-haven assets such as gold and the yen.
"Risk appetite has declined because of the Brexit vote," said Jeremy Zirin, head of investment strategy at UBS Wealth Management Americas in New York.
"Sectors that are performing well today are only those that have reacted positively to the dollar," he added.
The dollar fell 0.22 percent to 94.35 against a basket of major currencies.
The U.S. Federal Reserve left short-term interest rates unchanged on Wednesday and cut its forecast for economic growth, but stock markets' reaction to the largely expected outcome has been muted.
At 11:27 a.m. ET (1527 GMT), the Dow Jones Industrial Average was down 107.04 points, or 0.6 percent, at 17,626.06.
The S&P 500 was down 12.49 points, or 0.6 percent, at 2,065.5.
The Nasdaq Composite was down 45.46 points, or 0.94 percent, at 4,799.46.
Dow and S&P are on track to close down more than 1 percent for the week, while Nasdaq is down 2 percent.
Seven of the 10 major S&P sectors were lower, led by a 1.23 percent fall in the healthcare sector.
However, it was the 1.06 percent fall in the information technology index that weighed the most on the S&P.
Apple fell 2 percent to $95.59 after Bloomberg reported that the tech giant may have to halt the sales of its latest iPhones in Beijing after the devices were found to have violated a Chinese rival's patent.
Google's parent Alphabet was down 2.7 percent at $704.87.
Oracle rose 2.1 percent to $39.47 after the company reported better-than-expected quarterly revenue. The stock gave the biggest boost to the S&P.
Advancing issues outnumbered decliners on the NYSE by 1,650 to 1,241. On the Nasdaq, 1,402 issues fell and 1,215 advanced.
The S&P 500 index showed seven new 52-week highs and two new lows, while the Nasdaq recorded 22 new highs and 25 new lows. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Don Sebastian)