The S&P 500 was down 2.1%, as of 3 p.m. Eastern time, with the sharpest losses hitting stocks that most need a healthy economy for their profits to grow. The Dow Jones Industrial Average was down 567 points, or 2.4%, at 23,194, and the Nasdaq composite was down 2.2%.

Treasury yields were also lower in another sign of pessimism, after Federal Reserve Chair Jerome Powell warned about the threat of a prolonged recession. He said the U.S. government may need to pump even more aid into the economy, which is bleeding millions of jobs every week as collateral damage in the battle against the coronavirus pandemic.

The market has been wavering the last couple weeks after coming off its best month in a generation, as optimism about reopening the economy collides with worries about the dangers of lifting restrictions too soon.

”At this stage now, we think there are more risks to the downside than the upside,” said Liz Ann Sonders, chief investment strategist at Charles Schwab.

”Consumers in general are going to be more wary and more interested in boosting savings rates and are unlikely to come back to a world of consumption anywhere near what it looked like before,” she said.

Worries that the economic recovery may not be as strong or as rapid as investors had been banking on just a week ago hit oil companies and banks particularly hard.

Energy producers in the S&P 500 fell 4.8% for the biggest loss among the 11 sectors that make up the index. Financial stocks were close behind with a 3.2% loss. Those two areas of the market have been some of this year’s biggest losers this year on expectations for less demand for oil and lower profit from making loans.

Earlier in the day, strength for technology stocks had helped to steady the market momentarily. Tech stocks have been among the market’s few clear winners this year, as investors hunt for companies that can profit even in a stay-at-home economy. But the gains for tech quickly faded, and 90% of the stocks in the S&P 500 were down in afternoon trading.

Trading was erratic again, and the S&P 500 went from an early loss of 1.1% to a gain of 0.1% and back to more losses, all in the span of 90 minutes. The volatility echoes Tuesday’s action, when the S&P 500 was close to flat for much of the day before a sudden slide in the last hour of trading left it down 2.1%.

Analysts say they expect the market to remain in a wait-and-see approach for weeks as investors gauge how economic reopenings underway in areas around the world are going. Many countries and U.S. states have begun lifting restrictions on businesses that were meant to slow the spread of the coronavirus outbreak but have also sent the economy into a severe recession.

Hope that the reopenings will allow growth to resume later this year have helped drive the S&P 500 up 25% since late March, but worries have been rising recently that premature liftings of lockdowns will cause resurgent waves of infections.

Many professional investors were already skeptical of the rally, saying it was overdone given how much uncertainty exists about how long the recession will last. Worries about a resumption in trade tensions between the United States and China have also weighed on markets around the world recently.

On Tuesday, the top U.S. infectious diseases expert, Dr. Anthony Fauci, warned that if the economy reopens too soon, it could cause a backtrack in the “road to try to get economic recovery.”

In China, where the virus first surfaced, authorities announced seven new cases on Wednesday. Six were in Jilin province, in the northeast, where alert levels were raised and rail connections suspended. South Korea reported 26 additional cases of the coronavirus over the past 24 hours amid a new spike in infections linked to nightclubs in Seoul.

In Asian stock markets, Japan’s Nikkei 225 slipped 0.5%, the Hang Seng in Hong Kong lost 0.3% and South Korea’s Kospi rose 0.9%. In Europe, Germany’s DAX lost 2.6%, and France’s CAC 40 dropped 2.9%. The FTSE 100 in London lost 1.5%.

The yield on the 10-year Treasury fell to 0.64% from 0.69% late Tuesday. A barrel of U.S. oil to be delivered in June fell 49 cents, or 1.9%, to settle at $25.29. Brent crude, the international standard, fell 79 cents, or 2.6% to $29.19 a barrel.