Stocks fell sharply Thursday as financial market volatility driven by the spreading coronavirus rattles Wall Street for the second straight week.

The Dow Jones Industrial Average fell by roughly 740 points, a 2.7 percent drop, while the S&P 500 opened with a loss of 2.5 percent and the Nasdaq composite fell 2.3 percent. Thursday’s losses follow a tumultuous week for stocks after rallies on Monday and Wednesday punctuated by a Tuesday plunge.

A brief boost of Wall Street relief from former Vice President Joe Biden’s strong Super Tuesday victories gave way to deepening fears about the coronavirus and its impact on the economy.

Business and nonprofits have canceled hundreds of events planned for spring, U.S. airlines have scrapped flights and companies are bracing for widespread absences and school closures. 

Amazon and Facebook have asked Seattle-area employees to work from home after an employee of the online retail giant and a contractor for the social media platform tested positive for the disease.