soared within minutes of the announcement Wednesday. The pause applied to all countries except China, which investors had thought would face an import tax of 125%.

But stocks began to drop Thursday morning as analysts noted that even with the tariff pause, countries still faced a new blanket 10% tariff — already much higher than before. Tariffs recently imposed on cars and auto parts, as well as steel and aluminum, would also remain in place. Then the White House clarified that the new 125% tariff on Chinese imports was on top of earlier 20% tariffs, taking the number to 145%.

“Despite the good news, policy uncertainty remains elevated and will act as a drag on the U.S. economy,” James Rossiter, the head of global macro strategy at TD Securities, wrote in a note. “Firms will struggle to plan.”

Trump signaled an openness to negotiating with countries over the nearly across-the-board 10% tariff he had imposed. While describing it as a “baseline” at a Cabinet meeting on Thursday, he also seemed to say it could be subject to change. “It depends on what they’re adding,” he said.

Chief executives have begun to warn that uncertainty is challenging enough.

On Wednesday, Delta Air Lines said a lack of clarity about the economy prevented it from telling investors how much money it expected to make this year. Delta’s stock price tumbled more than 11% Wednesday.

Economists also warned that the remaining tariffs on China would still have enormous repercussions for the U.S. economy. Many public companies whose shares trade on the open market rely on imports from China. The clothing retailer Nike fell over 8% Thursday.

Wendong Zhang, an assistant professor of applied economics and policy at Cornell, pointed out that “many products that the U.S. imports are predominantly from China,” including 73% of smartphones, 78% of laptops, 87% of video game consoles and 77% of toys. “Resourcing from other countries will take time and result in much higher costs,” Zhang said in an interview Wednesday.

Few corners of the stock market were spared. More than 80% of the stocks in the S&P 500 ended the day lower. The energy sector led declines as oil prices tumbled, another harbinger of slowing global growth. The U.S. dollar weakened 1.7% against a basket of currencies of its major trading partners, its worst day of the year so far.

Carmax tumbled 17%, among the worst performing stocks in the index, after the company said it had become more challenging to forecast what was ahead.

“We are focused on growing the business, and we continue to make progress toward our long-term goals. However, we are removing the time frames associated with them given the potential impact of broader macro factors,” Carmax said in a statement as it reported quarterly results. Analysts expect that the 25% tariffs on imported cars that went into effect last week is likely to raise car prices, lower sales and cause other disruptions to the auto industry.

Rating agencies that score corporate debt based on how risky it is have begun to warn of rising defaults amid the economic fallout from tariffs. Measures of corporate borrowing costs have risen in recent days, a sign that lenders see more risk emerging for businesses.

The S&P 500 is again approaching a bear market, defined as a drop of more than 20% from its recent peak and a line in the sand for investors that marks a period of extreme pessimism.

The index has fallen 14.3% since its mid-February high. The tech-heavy Nasdaq composite index and the Russell 2000 index of smaller companies have already dropped into a bear market.

Officials at the Federal Reserve are keeping close tabs on recent gyrations in financial markets, especially after a sell-off across U.S. government bonds earlier this week, which undermined their status as a place for investors to shield themselves during market storms.

Government bonds held steady Thursday. The benchmark 10-year Treasury yield, which underpins borrowing across the economy, has risen from less than 4% on Friday to roughly 4.4% on Thursday.

Wall Street’s slump on Thursday came after major benchmarks in Asia and Europe had ended the day sharply higher. In Asia on Thursday, benchmark indexes rose more than 9% in Taiwan and Japan and 6% in South Korea. In Europe, the Stoxx Europe 600 index jumped more than 5%. The markets in Germany and France each gained more than 5%.

The Chinese government has taken steps to stabilize its markets. State-owned companies announced Tuesday that they were buying back some shares, a move that typically helps push stock prices higher. On Thursday, an influential state media outlet published a commentary saying it was a good time for the central bank to lower interest rates and take other steps that would support the economy.