Wall Street stocks rocketed higher Wednesday, boosted by a strong performance by US presidential candidate Joe Biden in the Super Tuesday primaries and extending a run of volatility amid coronavirus worries.
US indices last week suffered their biggest weekly losses since 2008. The roller-coaster continued this week, with stocks surging on Monday and plunging on Tuesday before Wednesday's rally recovered some of the ground.
The Dow Jones Industrial Average finished the session up 4.5 percent at 27,090.86, a gain of almost 1,200 points, recovering the 800 points lost Tuesday.
The broad-based S&P 500 jumped 4.2 percent to end the day at 3,130.12, while the tech-rich Nasdaq Composite Index surged 3.9 percent to close at 9,018.09.
As the new coronavirus continued to spread, Italy on Wednesday announced it was closing all schools and Israel moved to tighten travel restrictions on five more European nations.
The death-toll currently stands at more than 3,200 and a growing list of trade shows and public events have been postponed or canceled as economists slash their outlook for 2020.
But markets on Wednesday focused on election results from Tuesday in which former vice president Biden re-established himself as a frontrunner, winning at least nine and possibly 10 of the nomination contests held across 14 states.
Investors have been unnerved by the rise of leftist Bernie Sanders, who has emerged as Biden's top rival in the shrinking field of Democratic contenders. Sanders favors hefty taxes on wealth and a radical remake of the US healthcare system.
While stock gains were broad-based, health insurers were especially buoyant on expectations that Biden would seek more modest changes to the health care market in comparison with Sanders, who has sharply criticized insurers.
UnitedHealth Group surged 10.7 percent, Anthem won 15.6 percent and Humana jumped 14.4 percent.
Campbell Soup soared 10.1 percent after lifting its 2020 profit forecast, due in part to lower interest payments following moves to cut debt.