After a week of bloodletting, US stock markets rebound sharply

After some major bloodletting last week, the Dow Jones Industrial Average had its biggest single-day percentage gain since 2009 on Monday, rising nearly 1,300 points or more than 5%.

The S&P 500 and Nasdaq similarly rallied Monday, up by 4.6% and 4.49%, respectively, by the time trading closed.

The volatility left some analysts and experts scratching their heads, coming on the heels of major losses last week when the Dow suffered its worst week since the financial crash of 2008 amid uncertainty over the novel coronavirus.

The rally may signal that investors expect central banks and authorities to take action to help mitigate some of the economic impacts of coronavirus.

A U.S. Treasury spokesperson said that G7 finance ministers will hold a conference call Tuesday to discuss steps to deal with the economic impacts of the outbreak, and the call will be led by Treasury Secretary Steven Mnuchin and Federal Reserve Chairman Jerome Powell, Reuters reported.

On Friday afternoon, Powell issued a rare statement, saying they were "closely monitoring" the situation and "will use our tools and act as appropriate to support the economy."

On Monday, the Organization for Economic Co-operation and Development called on urgent government action to mitigate the economic impact of the outbreak, and slashed its global economic growth outlook.

The Dow’s best performers Monday included Apple, Walmart, United Health Group, Microsoft and The Travelers Companies. Apple shares rose by more than 9% and Microsoft by more than 6% during trading.

In a memo Sunday evening, Daniel Ives, the managing director of equity research at Wedbush Securities, put Microsoft and Apple both atop their list of top tech names to own "in this coronavirus sell-off."

"We view these times of fear and 'white knuckle' Street panic as witnessed over the past week with the coronavirus outbreak as, while tragic for the individuals and families impacted, representing golden buying opportunities to own the tech themes and stocks that we believe will be long term winners," Ives wrote.

Among the worst performers Monday were the Walt Disney Company, Dow Inc. and 3M Co., though even shares for those three were up by approximately 2%.

ABC News' Rebecca Jarvis contributed to this report.