CHICAGO (CBS) —  Trading was halted for 15 minutes as markets tumbled.

It came amid growing worries about the coronavirus, affecting the global economy and oil prices.

The Dow made a comeback, but it’s still down.

CBS 2’s Naomi Ruchim takes a look at what’s behind the sell-off.

The sell off began at the opening bell. The Dow Jones Industrial Average plummeted more than 1,800 points within the first minute and the S&P dropped more than 7% triggering a trading halt for 15 minutes.

“We have precautions and measures put in place to slow the markets down when it’s moving very quickly in either directions,” said Stacey Cunningham, President of the NYSE. “So that investors have an opportunity to take a  step back, understand what’s going on and react.”

A dispute between oil producing nations sparked the latest global sell off.

Demand for oil has slowed worldwide because of the growing coronavirus crisis. OPEC nations tried to make a deal to cut production in order to prop up prices, but it fell through sparking a price war.

“I’m going to call it a sort of a trade war between Russia and Saudi Arabia. The two largest powers in oil fighting is not good,” said floor trader Peter Tuchman.

Investors are already on edge about the impact of the coronavirus outbreak on the global economy. Many are seeking shelter in the safety of the bond market, pushing yields to new lows.

“This is really about uncertainty, and uncertainty creates that volatility until we understand the spread of the virus in the U.S. and efforts to contain and mitigate it, I think that volatility is likely to continue,” said CBS News Business Analyst Jill Schlesinger.

If the S&P 500 falls 20%, trading would halt for the remainder of the day.