U.S. equity markets soared in the final hour of trading as President Trump declared a national emergency over the coronavirus and enlisted the nation's biggest companies in the fight.

The Dow Jones Industrial Average posted its biggest one day point gain ever, surging by over 1,985 points or 9.3 percent. The S&P 500 and Nasdaq Composite also rallied over 9 percent.

Google, Walmart, Target, CVS and others will assist health officials in combating the outbreak and helping with procedures and testing.

The major averages rebounded from a Thursday selloff that was their steepest since the Black Monday crash of 1987. All three lost at least 9.5 percent amid an avalanche of cancelations and postponement of large social gatherings and sporting events aimed at slowing the spread of the new coronavirus.

Friday’s gains come as the U.S. Congress, which was supposed to recess on Friday, works overtime to pass a stimulus package. Meanwhile, reports indicate Europe is set to announce measures on Monday that could amount to 1 percent of gross domestic product.

Some of the hardest-hit corners of the market were among the biggest gainers on Friday.

The cruise operators Carnival Cruise Corp., Norwegian Cruise Line Holdings and Royal Caribbean Cruises, which have collectively seen nearly $50 billion -- or over 70 percent of their value -- erased amid the selloff, all gained at least 20 percent early in the session before paring their gains.