Oil prices drop below $ 100 a barrel as China’s Covid-19 outbreak threatens demand.

Oil prices fell below $ 100 a barrel on Tuesday as China, the world’s largest oil importer, imposed new lockdowns to combat a coronavirus outbreak, moves that could threaten demand.

The fluctuation in oil prices, which last week approached $ 130 a barrel, reverberated on the stock market: airline shares rose and oil producer shares slipped.

Brent crude, the global benchmark, fell 7.4% to $ 99.91 a barrel, the lowest price since late February. West Texas Intermediate, the US benchmark, fell 6.4% to $ 96.44 a barrel.

Over the past week, crude oil prices plummeted by more than 20%, reversing much of the surge after the Russian invasion of Ukraine added turmoil to an already struggling energy market. Tens of millions of residents in Chinese provinces and cities, including Beijing, Shanghai and Shenzhen, are in isolation due to the outbreak of the Omicron variant of the coronavirus. Travel between cities was cut off, production lines were cut off, and shopping malls were closed.

The measures could trap global supply chains that are still struggling to recover from disruptions to the pandemic by slowing major factory and transportation networks. Companies in China, including Foxconn, the Taiwanese electronics company that assembles Apple iPhones, have suspended operations in the country.

The new measures beat Hong Kong’s Hang Seng index, where many Chinese companies are listed. With a 5.7% drop on Tuesday, the index has fallen 10% so far this week and was at its lowest level since February 2016.

On Wall Street Tuesday, falling energy costs helped drive up stock prices. The S&P 500 was up 2.1%, with airline-led earnings. On Tuesday, American Airlines and United Airlines gained more than 9%, while JetBlue was up more than 7%. A data analysis released on Tuesday found that ticket sales for domestic flights in February surpassed those of the same month in 2019, the first since the pandemic began. The trend was supposed to continue in March, according to early data from Adobe.

Oil producers have collapsed. Chevron and Exxon Mobil both fell more than 5% and Valero Energy was down 6.8%, making them among the worst performers in the S&P 500.

Gas prices, which had been on the rise for weeks during the conflict in Ukraine, also fell slightly on Tuesday. The average price of a gallon of regular gasoline was $ 4,316, down from the high of $ 4,325 the day before, according to data from AAA.

Wall Street has been hit this year due to rising threats to the global economy. Inflation is rising at the fastest pace in 40 years, threatening consumer sentiment, and the sudden rise in oil prices in recent weeks has exacerbated the situation. Tuesday’s rally followed three days of losses that had left the S&P 500 down more than 12% for the year.

Federal Reserve officials began a two-day meeting on Tuesday and are expected to announce Wednesday that they will raise interest rates by a quarter of a percentage point as they begin a campaign to cool the economy.

Investors also weighed conflicting messages about the Ukraine-Russia conflict as a fourth round of negotiations between country officials resumed on Tuesday. Mykhailo Podolyak, a Ukrainian representative, said that Russia and Ukraine discussed a possible ceasefire and the withdrawal of troops from Ukrainian territory.

“There is so much information that investors are taking on board,” said Fiona Cincotta, senior financial markets analyst at Forex.com. Ms. Cincotta said investors may weigh domestic concerns over news from abroad and feel the US is a safer place to invest right now.

“With the spread of Covid in Asia and geopolitical tensions in Europe, America looks like the best of a bad bunch right now,” he said.