In a statement, Central Huijin did not identify the stocks it purchased, other than that they were exchange-traded funds, which are baskets of stocks that track indexes. The company said it would continue to increase its holdings in the future.

Stock benchmarks in Hong Kong, Shanghai and Shenzhen plunged on Monday, and shares of some of China’s biggest consumer technology and app companies suffered drastic losses.

Xiaomi, a smartphone maker that has branched out into electric vehicles, plummeted over 20 percent.

The e-commerce company Alibaba dropped 18 percent and Tencent, the company behind China’s most ubiquitous app, WeChat, fell 13 percent.

In a note on Monday, analysts at Morgan Stanley forecast that U.S. tariffs could have a “far greater growth drag” on China’s economy than more limited levies did in Trump’s first term. “The deflation loop is still alive,” they wrote.

And fear of what may come next.

In conversations with The New York Times over the weekend, bankers, executives and traders said they felt flashbacks to the 2007-8 global financial crisis, one that took down a number of Wall Street’s giants. Leaving out the brutal, but relatively short-lived market panic that erupted at the start of the coronavirus pandemic, the velocity of last week’s market decline — stocks fell 10 percent over just two days — was topped only by the waves of selling that came as Lehman Brothers collapsed in 2008.

Few companies have discussed their outlooks publicly since last week’s tariff announcements, but major banks including JPMorgan and Wells Fargo will begin holding investor calls to address their earnings (and prospects) on Friday.

The uncertainty was neatly exemplified by Daniel S. Loeb, a billionaire hedge fund manager, who on Saturday wrote on X: “Sometimes market bottom when things look most bleak.”

“Not a prediction,” he added, “but keeping an open mind.”

The measures would lead to higher inflation and slower growth than initially expected, Mr. Powell warned during an event in Arlington, Va., on Friday. He showed concern about the souring economic outlook, but his emphasis on the potential inflationary effect of the new tariffs made clear that it was a significant source of angst.

“Our obligation is to keep longer-term inflation expectations well anchored and to make certain that a one-time increase in the price level does not become an ongoing inflation problem,” Mr. Powell said. The Fed’s mandate includes two goals, fostering a healthy labor market and maintaining low, stable inflation.

Before Mr. Trump’s return to the White House, inflation was already proving to be stubbornly sticky, staying well above the Fed’s 2 percent target. Yet the economy had stayed remarkably resilient, leading the central bank to adopt a more gradual approach to interest rate cuts that culminated in it pausing reductions in January. At that policy meeting, Mr. Powell established that the Fed would need to see “real progress on inflation or, alternatively, some weakness in the labor market” to restart cuts.

But with inflation set to soar because of tariffs, it will take tangible evidence that the economy is weakening significantly to get the central bank going again. That could mean that rate cuts are pushed off until much later this year or even delayed until next year if that deterioration takes time to materialize.

“They will not be inclined to be pre-emptive to cut rates to avoid what may be a downturn,” said Richard Clarida, a former vice chair at the Fed who is now a global economic adviser at Pimco, an investment firm. “They’re actually going to have to see an actual crack in the labor market.”

Mr. Clarida said he would look for a “material” rise in the unemployment rate or a “very sharp slowdown, if not a contraction” in monthly jobs growth to account for what he expected would be a significant lurch higher in inflation.

The latest jobs report, which was released Friday, showed that on the eve of Mr. Trump’s latest tariff blitz, the labor market was far from cracking. Employers added 228,000 jobs in March, and the unemployment rate ticked up to 4.2 percent as participation in the labor market rose.

Any enthusiasm about the latest data was quickly overtaken by a torrent of worries about the economic outlook — concerns Mr. Trump’s top economic advisers sought to address on Sunday.

Kevin Hassett, director of the White House National Economic Council, acknowledged that the president’s approach could exacerbate inflation. “There might be some increase in prices,” he said on ABC’s “This Week.” But he insisted that Mr. Trump’s plan would ultimately reverse a long-running trend of importing lower-cost products in exchange for job losses.

“We got the cheap goods at the grocery store, but then we had fewer jobs,” he said.

Scott Bessent, the Treasury secretary, also sought to downplay the prospects of a recession, telling NBC’s “Meet the Press” on Sunday that there would be an “adjustment process.”

Economists across Wall Street are much more gloomy about the outlook. Many have sharply raised their recession odds alongside their forecasts for inflation. Those economists fear that Mr. Trump’s tariffs, which are a tax on imports, will eventually decimate consumer spending, squeeze businesses’ profit margins and potentially lead to layoffs that push the unemployment rate above 5 percent.

Many in this cohort expect the Fed to lower interest rates swiftly as a result, beginning as early as June. Federal funds futures markets reflect an even more aggressive response, with five quarter-point cuts priced in for this year.

Michael Feroli, chief U.S. economist at J.P. Morgan, is calling for a recession in the second half of this year, with growth declining 1 percent in the third quarter and another 0.5 percent in the fourth quarter. Over the course of the year, he expects growth to fall 0.3 percent and the unemployment rate to rise to 5.3 percent. Even as the Fed’s preferred inflation gauge — once volatile food and energy prices are stripped out — surges to 4.4 percent, Mr. Feroli forecasts that the Fed will restart cuts in June and then lower borrowing costs at every meeting through January until the policy rate reaches 3 percent.

Jonathan Pingle, chief U.S. economist at UBS, has penciled in a percentage point worth of cuts this year even as core inflation reaches 4.6 percent. He expects the unemployment rate to shoot higher this year before peaking at 5.3 percent in 2026. Economists at Goldman Sachs projected that the Fed would deliver three consecutive quarter-point cuts beginning in July.

But there are credible risks to this outlook. The prevailing one is that the inflation shock will be just too enormous for the Fed to look past it by the summer, especially if the economy has not yet deteriorated in a meaningful way.

“The burden of proof now is higher because of the inflation situation that we’re in,” said Seth Carpenter, a former Fed economist who is now at Morgan Stanley. “They have to get enough information that convinces them that the negative effects of slowing — and possibly negative — growth outweighs the cost to them of inflation.”

Mr. Carpenter said he expected no cuts from the Fed this year but multiple next year, bringing interest rates down to between 2.5 percent to 2.75 percent. Economists at LHMeyer, a research firm, have also shelved cuts this year, assuming there is no “full-blown” recession.

Perhaps the most important determinant of when the central bank will restart rate cuts is what happens with inflation expectations. Beyond a year ahead, expectations have stayed somewhat stable, aside from some survey-based measures that are seen as less reliable than others.

If those expectations begin to wobble in a more notable way, the Fed would become even more hesitant to cut and would need to see even more economic weakness than usual, said William English, a Yale professor and a former director of the Fed’s division of monetary affairs.

Eric Winograd, an economist at the investment firm AllianceBernstein, said Mr. Powell’s inflation-focused posture on Friday would help to avoid that outcome. “The name of the game is: You talk tough,” he said. “You keep inflation expectations where they are, and, by doing that, you preserve your ability to ease later if it’s necessary.”

A higher bar for interest rate cuts could put the Fed in a tougher spot with the Trump administration, Mr. English said. Up until last week, the president had been more subdued in his criticism of the central bank, compared with his first term. He had called for lower interest rates but sought to justify them by pointing to his plans to lower energy prices, among other reasons.

But as the rout in financial markets has intensified, Mr. Trump has turned his ire back toward Mr. Powell and the Fed. On Monday, Mr. Trump said the “slow moving” Fed should cut rates. At one point, the president appeared to suggest that the market rout was part of his strategy. He circulated a video from a user on Mr. Trump’s social media network that suggested the president was “purposely CRASHING” the markets in part to force the Fed to lower interest rates.

Pressed on the matter on Sunday, Mr. Hassett of the National Economic Council responded by saying that the Fed was independent, before adding: “He’s not trying to tank the market.”

Mr. Trump has already sought to chip away at the central bank’s longstanding independence from the White House by targeting the Fed’s oversight of Wall Street. His decision last month to fire two Democratic commissioners from the Federal Trade Commission has also reverberated widely, raising important questions about what kind of authority the president has over independent agencies and the personnel who run them.

At the event on Friday, Mr. Powell said he fully intended to serve out all of his term, which ends in May 2026. He has also previously been explicit that early removal by the president is “not permitted under the law.”

“The risk to the Fed’s independence is bigger now,” Mr. English, the Yale professor, said. “It just puts them right in the firing line.”

China’s investments and advances in manufacturing are producing a wave of exports that threatens to cause factory closings and layoffs not just in the United States but also around the globe.

“The tsunami is coming for everyone,” said Katherine Tai, who was the United States Trade Representative for former President Joseph R. Biden Jr.

President Trump’s steep tariffs announced on Wednesday, which have caused stocks in Asia and elsewhere to plunge, were the most drastic response yet to China’s export push. From Brazil and Indonesia to Thailand and the European Union, many countries have already moved more quietly to increase tariffs as well.

Chinese leaders are furious at the recent proliferation of trade barriers, and particularly Mr. Trump’s latest tariffs. They take pride in China’s high savings rate, long work hours and abundance of engineers and software programmers, as well as its legions of electricians, welders, mechanics, construction workers and other skilled tradesmen.

On state television Saturday night, an anchor solemnly read a government statement condemning the United States: “It is using tariffs to subvert the existing international economic and trade order” so as “to serve the hegemonic interests of the United States.”

Five years ago, before a housing bubble burst, cranes putting up apartment towers dotted practically every city in China. Today, many of those cranes are gone and the ones that are left seldom move. At Beijing’s behest, banks have rapidly shifted their lending from real estate to industry.

China is using more factory robots than the rest of the world combined, and most of them are made in China by Chinese companies, although some components are still imported. After several years of rapid growth, overall installations of new factory equipment have already jumped another 18 percent this year.

When Zeekr, a Chinese electric carmaker, opened a factory four years ago in Ningbo, a two-hour drive south of Shanghai, the facility had 500 robots. Now it has 820, and many more are planned.

As new factories come online, China’s exports are rapidly accelerating. They rose 13.3 percent in 2023 and then another 17.3 percent last year.

Lending by state banks is also financing a boom in corporate research and development. Huawei, a conglomerate making items as varied as smartphones and auto parts, has just opened in Shanghai a research center for 35,000 engineers that has 10 times as much space for offices and labs as Google’s headquarters in Mountain View, Calif.

Leaders around the world are struggling to decide whether to raise trade barriers to protect what is left of their countries’ industrial sectors.

China has been rapidly expanding its share of global manufacturing for decades. The growth came mainly at the expense of the United States and other longtime industrial powers, but also of developing countries. China has increased its share to 32 percent and rising, from 6 percent in 2000.

China’s factory output is bigger than the combined manufacturing of the United States, Germany, Japan, South Korea and Britain.

Even before Mr. Trump won a second term, Biden administration officials warned during their final year in office about industrial overcapacity in China. They raised some tariffs, notably on electric cars.

But during their first three years, Biden administration officials mostly focused on tighter export controls for technologies like high-end semiconductors, citing national security concerns. They left in place tariffs of 7.5 percent to 25 percent that Mr. Trump had imposed on half of China’s exports to the United States in his first term.

It remains uncertain how the president’s much tougher approach this time will play out. Tariffs have occasionally slowed China’s growth in exports, but not stopped it. Other nations are on high alert for the possibility that Chinese exports could be diverted elsewhere, threatening the economies of longstanding U.S. allies like the European Union and South Korea.

China’s automakers were preparing a push into the American car market in 2017, when Mr. Trump first took office. GAC Motor in Guangzhou, China, brought dozens of U.S. car dealers to the city’s auto show that November. The company announced plans to sell gasoline-powered sport utility vehicles and minivans in the United States by the end of 2019.

But GAC and other Chinese automakers canceled their plans after Mr. Trump included cars in his initial 25 percent tariffs several months later.

Chinese companies still sell almost no cars in the United States. That is unlikely to change: With Mr. Trump’s latest moves, Chinese carmakers now face U.S. tariffs as high as 181 percent.

Blocked in the United States, Chinese automakers have continued building factories and have pivoted their export campaigns elsewhere. Their sales have soared in Australia and Southeast Asia, taking market share from Japanese and American brands. In Mexico, Chinese carmakers held just 0.3 percent in 2017; by last year, it was over 20 percent.

Rapid sales gains in the European Union, and evidence of Chinese government subsidies, prompted E.U. officials last October to impose tariffs of up to 45 percent on electric cars from China.

China is not just building car factories. It has built more petrochemical refinery capacity in the past five years, for example, than Europe, Japan and South Korea together have created since World War II. And China is on track to build these refineries even faster this year. Petrochemicals are then turned into plastics, polyester, vinyl and tires.

Robert E. Lighthizer, who was the United States Trade Representative in Mr. Trump’s first term, said that the latest American tariffs “are long overdue medicine — the real root cause is decades of Chinese industrial policy that has created breathtaking overcapacity and global imbalances.”

China is exporting so much partly because its own people are buying so little. A housing market crash since 2021 has wiped out much of the savings of the middle class and ruined many wealthy families.

Tax revenues are falling, but military spending is rising rapidly. That has left the government wary of spending on economic stimulus to help consumers. China has offset its housing debacle instead with its export campaign, creating millions of jobs to build, outfit and operate factories.

Some Chinese economists have recently joined Western economists in suggesting that the country needs to strengthen its meager social safety net. At the start of this year, the minimum government pension for seniors was just $17 a month. That barely buys groceries, even in rural China.

The country’s best-known economist, Professor Li Daokui of Tsinghua University, publicly called in January for raising the minimum monthly pension several fold, to $110. The Chinese government could afford it, he argued, and extra spending by seniors would stimulate the entire economy.

Chinese officials rejected his advice. When the budget came out on March 5, it had an increase in monthly pensions — but it was just $3, bringing it to $20 a month.

The same budget included $100 billion for investments, including ports and other infrastructure that help exporters. And there was a new program to upgrade technology used in manufacturing across 20 Chinese cities.

“It is too soon to say what will be the appropriate path for monetary policy,” he said at a conference in Virginia.

For days, the market momentum has been almost entirely downward, bringing a dubious distinction in sight: a bear market, which is a decline of at least 20 percent from a market top. For the S&P 500, a bear market is already within shouting distance, a scant 2.6 percentage points away.

Investors may need to be very patient, and to hope that changes in tariff policy occur rapidly enough in Washington to turn the markets around and, more important, avert a recession.