Investors celebrated the reopening of the New York Stock Exchange by sending stocks soaring Tuesday, as the nation continues to unwind from pandemic shutdowns and more drug companies chase coronavirus cures.

The Dow Jones industrial average closed the day up 530 points, about 2.2 percent. The blue chips broke through the psychological threshold of 25,000 during an afternoon surge before giving back some of those gains and closing at 24,995.11.

The Standard & Poor’s 500 index jumped 36 points, about 1.2 percent, to finish at 2,991.77. The broad index cracked 3,000 for the first time since March during the session. The tech-heavy Nasdaq added 15 points, or about 0.2 percent, to close at 9,340.22. All three indexes are coming off strong finishes last week.

“With more signs of the worst of the virus being behind us, investors are beginning to focus on more countries reopening and the lifting of travel bans around the world,” Torsten Slok, chief economist for Deutsche Bank Securities said in an email. “More signs of reopening and more signs of travel bans being lifted creates more clarity for markets.”

Dow component Merck closed up 1.2 percent Tuesday after the pharmaceutical giant announced several advances against the novel coronavirus, including teaming with another company to develop a vaccine as well as new treatments for covid-19 patients.

Nine of 11 S&P stock sectors advanced, led by financials and industrials, which had been unloved sectors whose comeback is a sign that the slow recovery is broadening. Health and technology fell on profit-taking.

“Laggards like banks and industrials are leading, a sign that investors want to be in the market but searching for value,” said David Donabedian, chief investment officer of CIBC Private Wealth Management, in an email.

Shares in consumer cyclical stocks were showing big gains, particularly airlines. United Airlines surged 17 percent, American 15 percent, and Southwest and Delta each jumped 13 percent.

All but six of the 30 Dow blue chips were up on the day. Goldman Sachs led the pack at 9 percent. JPMorgan Chase advanced 7 percent. Raytheon Technologies and Dow chemical were big gainers.

Investors got other morsels of good news. The Commerce Department reported new-home sales climbed 0.6 percent in April, an unexpected increase as economists had forecast a 22 percent drop.

The Conference Board said its consumer confidence index improved to 86.6 this month from 85.7 in April. Economists had expected better, but the numbers bolster sentiment after weeks of dour economic data.

Merck joins several companies racing to develop a vaccine to stop a disease that has claimed nearly 100,000 American lives. Maryland-based Novavax reported that it entered human study for a coronavirus vaccine. Last week, Massachusetts-based Moderna announced that a small, early trial for its own candidate yielded positive results. Pfizer, Johnson & Johnson and others also are trying to develop a vaccine for use as early as this year.

“One of these is going to work,” Scott Gottlieb, former Food and Drug Administration commissioner, said Tuesday in an interview with CNBC.

The United States is showing signs of economic revival even as jobless claims surged toward 40 million last week. The unemployment rate spiked to 14.7 percent in April, the worst level since the Great Depression. The government will release May data next week.

Trump economic adviser Kevin Hassett in a weekend interview with CNN predicted that unemployment numbers will get worse before they begin to trend downward.

Unemployment, said Hassett, “is going to be quite a bit higher.”

Oil prices extended their comeback, as supply and demand rebalance with more people driving and producers slowing output. U.S. benchmark West Texas Intermediate crude was selling for nearly $35 per barrel Tuesday, more than triple the price of a month ago. Brent crude was selling for around $37. Though prices remain well below what most producers need to earn a profit, oil experts are encouraged by the momentum.

The New York Stock Exchange reopened its floor Tuesday for the first time since March 23. Most traders will continue to work remotely, and those who return will come back to a “new normal,” according to NYSE President Stacey Cunningham.

“We’re essential workers. We took a pause voluntarily because we wanted to learn more about the virus and about how to protect ourselves from it,” Cunningham said Tuesday on NBC. “What’s really critical is that reopen does not mean go back to business as usual.”

Protective measures for returning traders will include temperature checks, masks and plexiglass barriers to ensure social distancing, Cunningham explained in a Wall Street Journal column. Workers will also be “required to avoid public transportation” to “limit their exposure and preserve capacity for others.”

“Stocks trade better when the floor is open, with reduced volatility and fairer prices,” Cunningham wrote. “Recent data demonstrate that our trading floor saves investors millions of dollars each day by making transactions more efficient.”

European markets swelled Tuesday, with the STOXX 600 - Europe’s version of the S&P 500 - gaining 1.08 percent on the day. The French CAC was up 1.5 percent, Britain’s FTSE 100 was up 1.25 percent, and the German Dax gained a flat 1 percent.

Asian markets boomed overnight, seemingly ignoring rising tensions between the United States and China over a crackdown on pro-democracy activists in Hong Kong and China’s role in the coronavirus pandemic. Japan’s Nikkei was up 2.5 percent, the Shanghai Composite up 1 percent and Hong Kong’s Hang Seng a robust 1.9 percent.