A board displays market activity on the floor of the New York Stock Exchange (NYSE) on September 16, 2022 in New York City. AFP
Sales of Chinese products to foreign markets sank 14.5 percent on-year last month, a third consecutive drop and one that was bigger than expected.
US trade data from June also showed a decline in both exports and imports, figures that are "indicative of weaker demand overall at home and abroad," said Briefing.com analyst Patrick O'Hare.
About 15 minutes into trading, the Dow Jones Industrial Average was down 0.8 percent at 35,185.00.
The broad-based S&P 500 fell 0.8 percent to 4,482.66, while the tech-rich Nasdaq Composite Index shed 1.0 percent to 13,857.94.
The losses were a reversal from Monday, when the Dow rose more than one percent.
Among individual companies, UPS shares fell 2.1 percent as it lowered its full-year forecast.
It cited added costs associated with a new labor agreement and a hit from lost business from customers who diverted deliveries due to worries about a strike prior to the deal.
Eli Lilly surged 13.2 percent as it lifted its full-year forecast following a strong second quarter boosted by robust sales of its diabetes treatment Mounjaro and other drugs.
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