Stocks on Monday gave back last week’s gains, with the Dow tumbling nearly 600 points, amid a historic drop in oil prices and fears that a decline in new coronavirus cases and a gradual reopening of the U.S. economy may not be enough to draw wary consumers back into stores and restaurants.

“They’re going to go back with caution,” says J.J. Kinahan, chief market strategist of TD Ameritrade. “Let’s not get ahead of ourselves.”

Meanwhile, U.S. benchmark crude oil fell into negative territory for the first time ever. West Texas Intermediate for May delivery plunged about 300% to -$37.63 per barrel. The outsize drop was largely caused by unusually low trading volumes and the price for June delivery remained positive at about $20 after declining 12%, Kinahan says. The negative price signifies there’s virtually no market for oil and sellers must pay up to store crude supplies.

Still, he says the precipitous fall symbolizes the abrupt decline in global demand for oil as the pandemic discourages auto, air and other travel. Energy companies make up a relatively large share of Standard & Poor’s 500 companies.

Halliburton lurched between gains and sharp losses, even though it reported stronger results for the first three months of 2020 than analysts expected. The oilfield engineering company said that the pandemic has created so much turmoil in the industry that it “cannot reasonably estimate” how long the hit will last. It expects a further decline in revenue and profitability for the rest of 2020, particularly in North America.

The Dow Jones industrial average fell 592 points, or 2.4%, to 23,650. The S&P 500 index closed down 1.79% at 2,823. And the tech-heavy Nasdaq dropped 1% to 8,560.

Last week, the Dow rose 2.2%, largely on hopes that coronavirus cases were peaking nationwide and state and federal officials debate a phased-in lifting of stay-at-home orders. But Kinahan says Americans are likely to remain cautious for an extended period, leading to continued volatility for markets. Stock, he says, at least are trading in narrower ranges than the thousand point declines and spikes of a few weeks ago.

Also weighing on stocks this week is a first-quarter earnings season that will show the pandemic’s initial blow to company profits and reveal guidance for coming quarters that may be bearish, Kinahan says.

“The government can declare whatever they want in terms of encouraging people to get out and do stuff,” said Willie Delwiche, investment strategist at Baird. “Whether or not broad swaths of society do that remains to be seen. It’s going to take seeing people start to get out and do stuff again. That will be the necessary positive development, not just declaring getting things open.”

More gains from companies that are winners in the new stay-at-home economy helped limit the market’s losses. Netflix jumped 3.4% to set another record as people shut in at home look to fill their time. Amazon added 0.8%.

In Asia, Tokyo’s Nikkei 225 fell 1.1%. The Hang Seng index in Hong Kong lost 0.2%, and South Korea’s Kospi fell 0.8%.

European markets were modestly higher. The German DAX was up 0.5%, the French CAC 40 was up 0.7% and the FTSE 100 in London gained 0.7%.

In a sign of continued caution in the market, Treasury yields remained extremely low. The yield on the 10-year Treasury slipped to 0.62% from 0.65% late Friday.

Stocks have been on a general upward swing recently, and the S&P 500 just closed out its first back-to-back weekly gain since the market began selling off in February. Promises of massive aid for the economy and markets by the Federal Reserve and U.S. government ignited the rally, which sent the S&P 500 up as much as 28.5% from a low on March 23.

More recently, countries around the world have tentatively eased up on business-shutdown restrictions put in place to slow the spread of the virus.

But health experts warn the pandemic is far from over and new flareups could ignite if governments rush to allow ”normal” life to return prematurely. The S&P 500 remains nearly 17% below its record high as millions more U.S. workers file for unemployment every week amid the shutdowns.

Many analysts also warn that some of the the recent rally for stocks is due to expectations the economy will pivot quickly and rebound sharply once economic quarantines are lifted. Those could prove to be too optimistic.

“There’s still uncertainty surrounding the reopening of the economy,” said Julian Emanuel, chief equity and derivatives strategist at BTIG. “Come fall, are we going to be back on airplanes? Are we going to go out and eat?”

Contributing: Associated Press