Stocks recouped their early losses as investors stepped in to pick up shares at lower levels.
All three of the major averages opened lower on Monday, continuing Friday's selloff which came after a U.S. airstrike killed Iranian Gen. Qassim Soleimani, head of the Islamic Revolutionary Guard Corps' elite Quds Force, causing tensions to flare in the Middle East.
The Dow Jones Industrial Average fell more than 200 points, or 0.7 percent, before clawing back its losses. The S&P 500 and Nasdaq Composite were lower by as much as 0.6 percent and 0.8 percent, respectively.
Defense names, like Lockheed Martin, Northrop Grumman, Raytheon and General Dynamics were mixed after gaining on Friday.
Boeing was lower after an internal audit uncovered another potential design flaw with its best-selling 737 Max aircraft. The planemaker isn't expected to get the 737 Max back in service until February at the earliest.
Gold miners Barrick Gold and Newmont Mining traded mixed. As did energy giants Exxon Mobil and Chevron after the former released a regulatory filing that said its fourth-quarter results will be lower than a year ago.
As U.S. equity markets sold off, commodity prices rallied. West Texas Intermediate crude oil, the U.S. benchmark climbed 0.2 percent to $63.20 per barrel. It was up more than 1 percent earlier in the session.
Brent crude, the international benchmark, gained 0.4 percent to $68.86 per barrel. It was up more than 1.2 percent Monday morning.
In Asia, Japan's Nikkei slid 1.9 percent, Hong Kong's Hang Seng lost 0.8 percent and China's Shanghai Composite was little changed.
Meanwhile, the price of gold, which investors buy in times of uncertainty as a safe haven of value, rose 1.6 percent to $1,577 per ounce, its highest since April 2013, amid the heightened tensions in the Middle East.
U.S. Treasurys were little changed with the yield on the 10-year note holding at 1.79 percent.
In Europe, London's FTSE slipped 0.8 percent, Germany's DAX dropped 1.3 percent and France's CAC was down 1 percent.
Asian markets were mostly under pressure as Japan's Nikkei lost 1.9 percent, Hong Kong's Hang Seng fell 0.8 percent and China's Shanghai Composite was unchanged.
FOX Business' Ken Martin and the Associated Press contributed to this article.