A late day slide on Wall Street as investors continued to sort through the ramifications of rising tensions in the Middle East.
The Dow and S&P 500 ended lower.
The Nasdaq was basically flat helped by an upgrade for chip stocks.
Energy was the big loser of the day due to a one percent drop in oil prices.
Investors reversed some of the buying done in wake of last week's U.S. drone attack on a high-ranking Iranian official.
Chevron and Exxon Mobil were among the worst performing stocks in the Dow.
Nick Colas, co-founder of DataTrek Research, doesn't expect a prolonged market sell-off, because... SOUNDBITE (ENGLISH): DATATREK RESEARCH CO-FOUNDER NICK COLAS, SAYING: "The market understands the risks.
It understands what could happen but at the same time it also understands Fed policy is on our side, corporate profits are still very high, the U.S. economy is still fairly strong and it will take a really outsized oil shock - very high oil prices very quickly to really damage any part of that story.
So, take it in stride, understand that the market understands what is going on." Upbeat economic news limited the fallout from geopolitical rancor.
The U.S. trade deficit fell to a more than three-year low November thanks to a rebound in exports.
In a separate report, growth picked up in the U.S. services sector, according to the Institute for Supply Management's December survey.
On the corporate front: Investors snapped up shares of Boeing on unconfirmed chatter that Warren Buffet's Berkshire Hathaway was buying the stock.
Buffet's company and Boeing declined to comment.
And that wasn't the only Boeing news.
The trouble planemaker revised an advisory - and is now recommending pilots engage in hands-on training for the grounded 737 MAX, not just computer-based training.
The MAX has been grounded for 10 months after two fatal crashes.