The day's decline came a day after the Dow Jones Industrial AverageOpens a New Window. snapped a six-day winning streak.
Oil prices plunged more than 4 percent to $51.03 per barrel, weighed down by a weaker outlook for demand and a rise in U.S. crude inventories despite expectations of extended supply cuts led by OPEC.
U.S. crude oil inventories climbed 2.2 million last week, the U.S. Energy Information Administration said Wednesday. Analysts had expected inventories to fall by about 600,000 barrels. That hit oil company stocks.
The upshot of the trade and interest rate concerns left professional investors in a cautious mood.
"The continued market recovery is encouraging, the overall economic environment remains supportive, and neither of the likely shock factors is necessarily indicating an immediate risk," Brad McMillan, chief investment officer for Commonwealth Financial Network, said to FOX Business.
"But the rising signs of economic weakness, combined with the fact that several of the market indicators continue to point to an elevated level of risk, suggest that volatility may return.
The pullback at the start of this month, on trade worries, only reinforces that possibility." Read more at FOX Business