Global stock markets are plunging as the threat from the coronavirus continues to spread across the world. Stock markets in Europe and Asia plunged ahead of markets opening in America. And when those U.S. markets opened, things were no different on this side of the Atlantic.

As CNBC points out, within minutes of opening, the Dow plunged 1,800 points. The S&P was down 7%. And with those falls major stocks crashed, too. At the time of this writing Apple, Amazon, Google, and Facebook are all down 7%. The drop in the markets happened so quickly it caused the automatic engagement of a market “circuit breaker,” which prevents traders from buying or selling for 15 minutes. The aim of these circuit breakers is to make people take a step back and breathe–and hopefully avoid panic trading when trading resumes.

The volatility in the markets has led to the hashtag #BlackMonday trending on Twitter. “Black Monday” is, of course, a reference to large stock market crashes, particularly the one that happened in October 1987, which saw the Dow lose over 22% of its value in a single day.

Whether today ends up being a new Black Monday in the history books, of course, depends on how trading continues throughout the day. The only certainty one can assume is that it will be a volatile day on the market thanks to fears of the impact the spread of the coronavirus is having on the world economy and the oil price war that has been launched by the Saudis.

As the BBC reports, Brent oil futures sunk to as low as $31 today after Russian and Saudi Arabia could not come to an agreement to scale back production–something that is needed because oil production is far outpacing current demands. As a result, oil prices sank to their lowest since the 1991 Gulf War, which has also contributed to today’s market selloff.