The Dow Jones Industrial Average piled on more than 900 points, or 3.9 percent, to 24,597.37.
The broad-based S&P 500 jumped 3.2 percent to 2,953.91, while the tech-rich Nasdaq Composite Index gained 2.4 percent to 9,234.83.
The rally followed a press release from US biotech firm Moderna that reported “positive interim” results in the phase 1 test of a vaccine candidate. A Phase 3 trial, the largest and most important to validate the efficacy of a vaccine, should begin in July.
Shares of Moderna shot up 20 percent.
Briefing.com said “caution” was needed given that the testing is still so preliminary, but added that “today’s news is a key step to getting back to normal.”
Moderna’s announcement lifted the market generally, but had an especially beneficial impact on companies in travel, entertainment and other sectors that have been hit hardest by the COVID-19 shutdown.
This group included United Airlines, up 21.1 percent, Marriott International, up 17.4 billion, live events company Live Nation, up 15.3 percent and shopping mall owner Simon Property Group, up 10.9 percent.
Analysts said there were some secondary factors that supported stocks, including the steps by more states in the US to reopen their economies and a broadcast interview with Federal Reserve Chairman Jerome Powell, who said the economic downturn would not be as bad as the Great Depression.
Among other stocks, Uber Technologies rose 3.6 percent as it announced it is cutting a quarter of its global workforce to survive the financial hit to its business from the coronavirus pandemic, impacting around 3,000 employees.