5 things to know before the stock market opens Monday

U.S. stock futures were pointing to about an 800-point or 2.9% decline at Wall Street's open on Monday for the Dow Jones Industrial Average. However, European stocks were faring worse, with Italian equities down 4% as Italy grapples with the largest coronavirus outbreak outside of Asia, with more than 150 reported cases and four deaths. On Sunday at the G-20 summit in Riyadh, Saudi Arabia, Treasury Secretary Steven Mnuchin told CNBC that U.S. officials will have a better idea of how the coronavirus spread will impact the economy in "three or four weeks." Outbreak concerns were already intensifying last week, sending the Dow down 227 points or 0.8% on Friday, breaking a two-week winning streak.

Investors were buying U.S. Treasury bonds in a perceived flight to safety — pushing yields, which move inversely to prices, sharply lower. The 10-year Treasury yield sank below 1.4% and the yield on the 30-year hit new all-time lows around 1.83%. Gold was surging about 2% in Monday trading after soaring nearly 4% for all of last week. The dollar was also stronger on Monday versus currencies in Asia and Europe.

Billionaire investor Warren Buffett, who joins CNBC's "Squawk Box" for three hours ending at 9 a.m. ET, said Monday that he views the stock market's huge decline as a buying opportunity. "We're a net buyer of stocks over time. When stocks are down we're going to be buying on balance. Would rather buy at a lower price than a higher price," he said. Click here to keep up with everything Buffett says on CNBC on Monday morning. On Saturday, he released the most widely anticipated shareholder letter of the year and discussed how Berkshire Hathaway's business fared throughout 2019.

In addition to an explosion of coronavirus cases in Italy, South Korea cases climbed to more than 830, with seven deaths. Health authorities said that global cases rose to nearly 79,500 with over 2,600 deaths — still with the vast majority of cases and deaths in China where the new virus originated. Chinese leaders decided Monday to postpone the third session of the 13th National People's Congress, according to state media. The annual event in Beijing, at which China releases economic targets for the year, had been set to begin next week. No future date was given.

Sen. Bernie Sanders will win Saturday's Nevada Democratic caucuses, NBC News projected, strengthening his early pole position in the race for the presidential nomination. Former Vice President Joe Biden, whose campaign needed a boost after poor results in Iowa and New Hampshire, will finish second in Nevada. Ex-South Bend, Indiana Mayor Pete Buttigieg came in third, according to NBC News. Sen. Elizabeth Warren trailed in fourth. South Carolina holds its primary this coming Saturday ahead of Super Tuesday on March 3, when a third of the delegates are up for grabs in 16 nominating primaries and caucuses.