Wall Street stocks were mostly lower early Wednesday, extending a choppy period in markets, with analysts pointing to global growth concerns and disappointing US private hiring figures.
Hiring by American private firms slowed sharply in July to 330,000, with dramatically lower gains in the construction and leisure and hospitality sectors, according to payroll services firm ADP.
The disappointing data come ahead of Friday's much-anticipated government employment report, which is expected to show a gain of as much as a million jobs.
The weak figures will foment the narrative that the US economy has reached "peak growth," said Briefing.com analyst Patrick O'Hare.
About 35 minutes into trading, the Dow Jones Industrial Average was down 0.4 percent at 34,993.62.
The broad-based S&P 500 shed 0.2 percent to 4,414.41, while the tech-rich Nasdaq Composite Index was unchanged at 14,661.18.
After falling on Monday and the first part of Tuesday, stocks rallied Tuesday afternoon, lifting the S&P 500 to a fresh record.
Among individual names, Robinhood Markets surged more than 40 percent, with US financial news site CNBC pointing to strong support from users on the Reddit platform in the latest example of the rising ability of retail investors to dramatically move stock prices.