U.S. stocks were lower on Tuesday, with declines in Facebook, internet stocks and Nike leading to a bumpy start to September, as investors also grappled with rising trade uncertainties.
Facebook fell 2.5 percent after brokerage MoffettNathanson downgraded the social media giant to "neutral", citing revenue growth deceleration.
Other internet stocks Alphabet, Twitter, Snap fell between 1 percent and 2.4 percent, while the S&P technology index dropped 0.3 percent.
Nike dropped 2.7 percent as the company faced backlash over its choice of Colin Kaepernick, the first NFL player to kneel during the national anthem as a protest against racism, as a face for the 30th anniversary of its "Just Do It" slogan.
The losses came after a strong August for the main U.S. indexes despite rising concerns over trade.
"Since August was a good month for stocks, we are seeing some profit-taking and the headlines on China negotiations seem to be weighing a little bit as well," said Sean O'Hara, president of Pacer ETFs in Paoli, Pennsylvania.
Helping curb losses was Amazon.com, whose shares rose 1.8 percent in their seventh straight day of gains, hitting yet another record and joining Apple in the $1 trillion market cap club.
The public comment period on a U.S. proposal for new tariffs on Chinese goods is set to end on Sept. 5, after which U.S. President Donald Trump can follow through on plans to impose levies on $200 billion more of Chinese imports, though it is unclear how quickly that will happen.
Talks between Canada and the United States to renegotiate the North American Free Trade Agreement (NAFTA) ended on a sour note on Friday, but officials set plans to resume their talks on Wednesday.
At 11:35 a.m. ET the Dow Jones Industrial Average was down 63.75 points, or 0.25 percent, at 25,901.07, the S&P 500 was down 6.52 points, or 0.22 percent, at 2,895.00 and the Nasdaq Composite was down 19.93 points, or 0.25 percent, at 8,089.61.
"This is not an enormous move, seems like day-to-day volatility for September," O'Hara said.
The indexes pared losses after data from the Institute for Supply Management showed U.S. manufacturing activity accelerated to more than a 14-year high in August, boosted by a surge in new orders.
Six of the 11 major S&P 500 sectors were lower, led by a 1.12 percent drop in the telecom sector.
Verizon fell 2 percent after Barclays downgraded the wireless carrier's stock.
Advanced Micro Devices gained 7.6 percent and Qualcomm was up 2.6 percent after brokerages upgraded the chip stocks.
Declining issues outnumbered advancers for a 2.01-to-1 ratio on the NYSE and a 1.85-to-1 ratio on the Nasdaq.
The S&P index recorded 45 new 52-week highs and seven new lows, while the Nasdaq recorded 114 new highs and 38 new lows.