After the dot-com bubble burst in the early 2000s, Lars Staack decided to play it safe and invest his retirement savings in S&P 500 index funds, which are diversified and carry lower risk than owning individual stocks.

It was a strategy that brought him peace of mind for more than two decades — until President Trump was elected in November. As he reviewed Mr. Trump’s comments in support of sweeping tariffs, Mr. Staack, 62, who retired two years ago, became increasingly uneasy about the savings he planned to use for the rest of his retirement.

Those nerves about how Mr. Trump’s economic policies might affect the stock market led him to start selling his index funds in January, moving them into bond and Treasury funds, which are seen as safe havens in times of volatility. About a third of his savings are still in stocks. The daily swings this past week, which included the market’s worst single day in months, have made him consider moving even more of his assets into safer bonds, he said.

“I’m fumbling about, trying to figure out what is going to be the best way to preserve my retirement savings from a volatile economy, and from upcoming inflation,” Mr. Staack said.

Many financial advisers are reiterating their usual advice during moments of angst: Do nothing and stay the course, assuming your financial plan is diversified and aligned with your goals. But the tumultuous rounds of trading have jolted people like Mr. Staack, who has an immediate need for his investments. The way he sees it, stock market index funds are no longer safe for people close to or in retirement — people who intend to use their assets in the near future and do not have the luxury of time to wait for the market to reverse course.

“What Trump and Musk have done is unprecedented, so it seems like nothing is safe anymore,” Mr. Staack said. He lives in Poway, Calif., outside San Diego, and was a Republican voter until 2016, when he started voting for Democrats.

Over the past few weeks, Wall Street has become increasingly pessimistic about whipsawing policies from Washington. By Thursday, the S&P 500 index had tumbled 10.1 percent from a peak that it had reached less than one month before, a sell-off fueled by investors’ fears that trade wars and mass layoffs of federal employees could prompt an economic slowdown. The S&P 500 correction underscored how the two-year-long bull market is running out of steam in the early days of the Trump administration.

Policy and politics have been the key driver of concern among clients, financial advisers said. But not everyone is taking action. In fact, advisers at some of the biggest wealth management firms said their clients were, for the most part, sticking with their existing financial plans.

Most of the roughly seven million investors on the Vanguard brokerage platform have “stayed disciplined,” in line with their behavior during market downturns in the past, said James Martielli, Vanguard’s head of investment and trading services. On Monday, when Wall Street suffered its steepest decline of the year, only 2.5 percent of Vanguard’s clients placed trades, and the majority of those trades were to buy equities, rather than sell them, Mr. Martielli said.

“Most clients right now are a little bit dazed, but still relatively comfortable where they’re at and where things are going,” said Mark Mirsberger, the chief executive of Dana Investment Advisors, which manages about $8.5 billion for institutions and individuals.

In conversations with clients, it is often retirees, and those closing in on retirement, who are paying the closest attention to the stock market and expressing nervousness, said Rob Williams, the managing director of financial planning and wealth management at Charles Schwab. The question, he said, is how they respond.

For people closer to retirement, “taking some risk off the table” might make sense, but when politics becomes a factor in decisions, which seems to be happening more, Mr. Williams said, he urges clients to stick to their plans and “not respond emotionally.”

Siegfried Lodwig is more than a decade into his retirement, and the recent volatility has not changed his mind about keeping about half of his savings in the stock market, managed by a financial services firm. He said he trusted that the market would bounce back, as it always had.

Still, Mr. Lodwig, 80, said he planned to leave his estate to Amherst College, where years ago he received a scholarship. He said he had some concern about how much would be left for the school if the market continued to fall in the short term.

Andy Smith, the executive director of financial planning at Edelman Financial Engines, is cautioning his clients not to overreact to news headlines about Wall Street’s jitters. Those with diversified portfolios and enough cash on hand for their short-term needs are able to calm their nerves with greater ease, he said.

“In times of volatility, everybody gets uneasy,” said Heather Knight, a national brokerage coach at Fidelity Investments. “Stay the course — that’s the best way to weather through some of those periods of volatility.”

But for some Americans — especially those who anticipate needing access to their savings in the near future — the current economic unease feels different from market dips they have experienced in the past, prompting them to rethink their investments.

Praisely McNamara, a single mother whose 16-year-old son is a junior in high school, decided in February to withdraw half of her 401(k), the maximum amount she could, despite having to pay thousands in tax penalties to do so. Employed in health care sales, she is still contributing to a Vanguard index fund. But with mortgage and college tuition payments on the horizon, the economic instability spurred by Mr. Trump’s policies was enough for her to feel that she needed cash on hand.

As someone without a stockpile of savings, Ms. McNamara, of Newington, Conn., said uncertainty about trade wars and the outlook for the U.S. job market had fueled her decision.

“This is absolutely the first time that I have felt in any way like I’m not secure in what I’ve been told is the most secure way to prepare for retirement,” said Ms. McNamara, 40, who voted for former Vice President Kamala Harris.

The volatility has rattled even Americans who do not expect to use their savings in the near future.

Alison Greenlaw, 43, is still a couple of decades away from retiring. She and her husband bought their home in Bloomfield, Conn., a few years ago. (Ms. Greenlaw knows Ms. McNamara through a community organization.) Until three weeks ago, her 401(k) was in a Vanguard target date retirement fund, which had a pre-mixed blend of stocks and other holdings based on the assumption that she would retire around 2045.

But as economic concerns started to creep into the stock market in February, she decided to move all of her 401(k) savings into a Vanguard money market fund, which has lower-risk investments like government-backed securities.

“I know I won’t make any money there, but I’m not freaking out like everyone whose 401(k) is losing money every day,” Ms. Greenlaw said. “I’m feeling glad that I did what I did,” she added, pointing to the market’s tariff-induced swings this past week.

Ms. Greenlaw tried to make an informed decision by talking to people who work in finance and whose opinions she respects. Many of them advised her not to do anything. But she said she was not comfortable taking the traditional wait-and-see approach. She said she felt that the level of uncertainty in the United States right now was “existential.”

On Tuesday, Stephen Dinan, 55, whose children are 5 and 7 years old, moved their 529 college savings accounts from U.S. stocks and stock index funds into bonds and an international equities index fund. He also moved his 401(k), along with his wife’s, into bonds.

Mr. Trump’s unpredictable and aggressive approach to policy has stoked Mr. Dinan’s worries about instability in the stock market. A Democratic voter, he said he hoped to move his savings back into stocks when the economic outlook cleared, or when there was a change in administration down the line.

Financial experts are “focused on things that are moving within the game as it’s played,” he said. “But they’re not planning for if the board game itself is taken out from under.”

After climbing into a Tesla Model S last week, President Trump pledged to buy one. The next day, the Fox News host Sean Hannity said he had bought a Model S Plaid to support the embattled company, saying a Tesla “has more American parts in it than any other car made in our country.”

In a backlash to the backlash against the tactics of Elon Musk’s Department of Government Efficiency, prominent conservatives are rallying to the side of the electric car company led by Mr. Musk. They are hoping to swing enough like-minded consumers to offset a boycott of the electric automaker by liberals and Democrats or anyone offended by Mr. Musk’s actions.

But how effective can such a rescue mission be? Analysts say it can help but only to an extent.

So many Democratic buyers appear to be fleeing Tesla that even Mr. Trump’s best sales pitch is unlikely to woo enough new customers to fill the vacuum, auto experts said. Analysts at JPMorgan predict Tesla will deliver its fewest cars in the first quarter than it had in three years.

“When you make your product unattractive to half the market, I promise you, you won’t increase your sales,” said Alexander Edwards, president of Strategic Vision, an automotive research and consulting firm.

Mr. Edwards has been surveying car buyers for decades. Since 2016, the surveys have found that electric-car owners were up to four times as likely to identify as Democrats or liberals as to identify as Republican or conservative. Among Tesla owners, the spread was consistently two to one.

The gap narrowed sharply through 2024. This year, as sales have fallen, slightly more Tesla buyers identify as Republicans than Democrats, at 30 percent versus 29 percent.

“Democrats are fleeing the brand and saying they won’t consider it in the future, so there is naturally a greater proportion of Republican and independent buyers,” Mr. Edwards said.

He said Democrats first started losing interest in Tesla when Mr. Musk bought Twitter, now X, in 2022. Then, last July, when Mr. Musk publicly backed Mr. Trump, the share of Democrats who said they would “definitely consider” a Tesla fell by half.

Overall, about 8 percent of car owners would now definitely consider a Tesla, according to Mr. Edwards’s surveys. That compares with 22 percent five years ago, when Tesla often topped rankings of luxury brands that buyers would consider.

Tesla’s slipping sales, he said, “are mostly, if not completely, attributed to the statements and behavior of Elon Musk.”

The automaker did not respond to a request for comment.

Tesla remains America’s best-selling electric vehicle brand by far with about 44 percent of the market, despite a 5.6 percent drop in U.S. sales, to about 634,000 cars in 2024, according to Kelley Blue Book. Many drivers are determined to stick with the electric vehicle pioneer, whose cars can travel several hundred miles on a charge and can be easily refueled at the company’s extensive charging network.

Josh Anders, 44, traded a gasoline-powered sport utility vehicle for a Tesla Model 3 in 2019. A resident of Fort Wayne, Ind., he was blown away by the car’s energy efficiency, technology and limited maintenance needs. He soon traded for another, and is about to take delivery of the latest Model Y S.U.V.

“Owning a Tesla was one of the best decisions I ever made, and I’m sticking by it,” Mr. Anders said. “I would love a Rivian R1S, but I can’t afford it. I’m a tech guy, and I love all the features and innovations.”

Mr. Anders, a father of four and creative director of a Christian nonprofit music and arts organization, said he leans conservative, and is uncomfortable with boycotts.

“Elon’s not perfect, and Tesla’s not perfect, but it’s a community of dreamers and doers. I appreciate a brand that’s constantly pushing the boundaries,” he said. “I don’t need every company to share my beliefs. I just need them to share a commitment to progress.”

Still, cars have a long history of becoming part of the political fray.

The Chevrolet Volt, a plug-in hybrid introduced in 2011 after General Motors received federal government assistance, was derided by some conservatives as the “Obamacar.” The fuel-sipping Toyota Prius and the gas-guzzling Hummer from G.M. were often lauded and attacked by people on opposite ends of the political spectrum.

Isaac Seliger, a business owner and grant writer in Scottsdale, Ariz., said he’d had little interest in electric vehicles even though his son, who died recently, was a devoted fan of Tesla.

Now, said Mr. Seliger, who described himself as politically independent, he is determined to buy a Tesla, because he wants to defy groupthink and polarization. A friend told him that she would stop speaking to him if he did.

“As a former lefty and antiwar guy, this all makes me want to buy a Tesla more,” Mr. Seliger, 73, said. “I’ll absolutely be making a political statement. But if I bought a Porsche Macan, that’s a statement, too, where people pigeonhole you as an obnoxious older Porsche driver.”

Mr. Seliger added that he found criticisms of Mr. Musk overblown.

“So Elon was a hero of the left, and now he’s a Nazi? That’s just crazy,” he said. “He strikes me as a smart guy who makes great stuff.”

To many people who have faith in Tesla and Mr. Musk, the company’s sales and stock price, which is down about 48 percent from a December high, will eventually recover. The stock was up 12 percent over the last four days of trading.

But some automotive experts say Tesla may struggle because the company has not regularly updated its cars or introduced new models. In addition, the company’s chargers, which once could be used only by Teslas, are opening access to nearly every major competitor, said Loren McDonald, chief analyst at Paren, an electric vehicle charging data firm. And other automakers are offering new electric models, often with notably affordable monthly payments.

“He’s rapidly losing the advantages in range, tech, value and convenience that drove people to Tesla,” Mr. McDonald said. “For a lot of people, it’s time to move on and try something new.”

Of course, most buyers don’t choose cars based on politics. But a brand’s image matters. Tesla sales slipped even as overall U.S. electric vehicle sales grew 7.3 percent in 2024, to 1.3 million. Mr. Edwards said Mr. Musk was making it too easy for people to shop elsewhere.

“People can love their Hyundai, G.M., Rivian or BMW just as much,” he said.

Republicans certainly buy electric cars, but fewer of them have made the plunge to fully electric models. Rural states, where Republicans outnumber Democrats, have fewer chargers than more urban states. Strategic Vision data shows Republicans are more likely to work outside the home, and are less willing to put up with inconveniences like long charging stops. And a 2024 Pew Research Center survey found that more Republicans than Democrats say electric vehicles cost too much and are less reliable than gasoline cars.

In the New York metropolitan area, the nation’s largest car market, new Tesla registrations fell 13 percent, to 47,000 cars, in 2024, according to S&P Global Mobility. That same year, more than 101,000 people registered a Tesla in Los Angeles, the second-largest market, a drop of 8 percent. Still, nearly one in eight new cars in Los Angeles was a Tesla. In the San Francisco Bay Area, where Tesla was founded, nearly one in five new cars was a Tesla. But sales tumbled 17 percent to 54,000 cars.

Consumers in the Houston area bought 12,000 Teslas. But Bay Area residents bought 4.5 times as many Teslas, in a smaller market for new cars overall. Some areas saw big increases, including Miami-Fort Lauderdale where sales jumped 32 percent, to nearly 23,000 cars, in 2024. Tesla sales also rose sharply in Salt Lake City, Las Vegas and St. Louis. But the company’s gains in these places could not offset steeper declines in larger, more liberal metro areas.

Experts say wealthy conservatives such as Mr. Hannity and Mr. Trump have the disposable income to make a personal automotive statement by opting for a Tesla. But they may not be able to persuade Americans of more modest means.

Mr. McDonald also noted that Mr. Trump and other conservatives had spent years vilifying electric cars, mocking climate change and criticizing former President Joseph R. Biden Jr.’s climate and auto policies.

“The messaging is inconsistent,” Mr. McDonald said. “Is the guy in Arkansas who drives a Ram pickup going to buy a Tesla now? How far can you go against your own beliefs to support Elon Musk?”

French Champagne producers do nearly a billion dollars’ worth of business with the United States every year. But on Friday in Épernay, the world capital of sparkling wine, the only number on anybody’s lips was 200.

That was the percent tariff that President Trump has threatened to impose on Champagne and other European wines and spirits exported to the United States, in a trade war that exploded this past week after the European Union countered Mr. Trump’s penalties on steel and aluminum with its own duties on American products.

The triple-digit menace landed like a thunderbolt in Épernay, rattling workers in nearby fields, producers in small villages and the venerable houses that line the Avenue de Champagne, Épernay’s central boulevard and a UNESCO Heritage site that oozes tasteful wealth.

“A 200 percent tariff is designed to make sure that no Champagne will be shipped to the United States,” said Calvin Boucher, a manager at Michel Gonet, a 225-year-old Champagne house on the avenue. With 20 to 30 percent of the 200,000 bottles it makes yearly exported to American wine merchants and restaurants, “that business would be crushed,” he said, adding that the price of a $125 Champagne would more than triple overnight.

Épernay sits in the heart of a region that produces the world’s finest bubbly. The United States is its biggest foreign market, with 27 million bottles shipped there in 2023, valued at around 810 million euros ($885 million).

Chardonnay, Pinot Noir and Meunier grapes blanket the rolling hills and deep valleys of Champagne, which covers more than 130 square miles, from the city of Reims to the Aube river. The area is under France’s strict Appellation d’Origine system, which ensures that only the sparkling wine made here, using specific methods, can legally be called Champagne.

With more than 4,000 independent winemakers and 360 Champagne houses, the region produces around 300 million bottles annually, with one billion more resting in cellars. The biggest houses — including Dom Pérignon, Veuve Clicquot and Moët & Chandon, owned by the luxury conglomerate LVMH Moët Hennessy Louis Vuitton — dominate production and exports and account for a third of total sales.

But such figures were of little comfort in the wake of Mr. Trump’s threat. Just off the Avenue de Champagne, Nathalie Doucet, the president of Besserat de Bellefon, a specialty Champagne house that exports 10 percent of its premium production to the United States, said that the trade war made her anxious.

“We are waiting to see what happens, but it’s not good news,” said Ms. Doucet, whose Champagne is made with a laborious low-pressure process that gives it a crisp acidity and fine effervescence.

Champagne already had a tough year with bad weather that had reduced the harvest. Consumption has declined as young people shifted habits and switched to cocktails and artisanal beer. Champagne sales have thinned since the pandemic, falling 9 percent last year.

At the same time, she said, Europe was grappling with wars in Ukraine and Gaza. And now the trade war with the United States, one of France’s traditional allies, over issues that have nothing to do with Champagne, has made her feel like collateral damage.

“It seems like a deliberate punishment,” said Cyril Depart, the owner of the Salvatori wine shop, just off the avenue, which offers a wide variety of artisanal Champagnes. His wife was an export manager for one of the big Champagne houses and had already been crunching numbers on the potential impact.

Leah Razzouki, an Épernay resident whose family has worked in the Champagne business for generations, said she was infuriated. “Many of our friends are small producers and they would be hit very hard,” she said.

The damage of a trade war would spread far beyond Champagne’s regal houses, hitting American importers and distributors and putting numerous small businesses at risk.

Michael Reiss, the president of Vineyard Road, a small distributor in Framingham, Mass., that imports Champagne and wines from Europe and distributes them in New England, said that small businesses like his, including restaurants and retail shops, would be “very hurt.” The unpredictable trade environment could force businesses to cancel planned investments, he added.

Adding to the pain, tariffs applied at the beginning of the supply chain can multiply, as each business handling the product marks it up accordingly, Mr. Reiss said. “So even a 25 percent tariff can easily lead to a 40 to 60 percent increase in prices,” he said.

A 200 percent tariff “would eliminate the possibility of people buying things that bring them joy in their lives,” he added.

Even inside the Champagne Museum bordering the avenue in Épernay, the chatter strayed to Mr. Trump’s tariffs. Sacha Raynaud, whose family owns a small Champagne house, had brought a friend to learn the history of Champagne, which first appeared in the 17th century on the tables of royalty, giving the drink its nickname, “the king of wines.”

“French people are waking up to what’s happening in the United States, and starting to speak about boycotting American products,” she said.

Similar worries circulated in the fields. Working in a buttery morning light, a dozen field hands secured knotted brown vines to wires ahead of the spring growing season on freshly plowed earth in the shadow of the Champagne-producing town of Reuil, just west of Épernay.

Even these jobs were at risk, said Patrick Andrade, who runs a small company that helps maintain Champagne vineyards. The 12 hectare (30 acre) plot belonged to a small house that exports to the United States, he said.

Should sales fall, wine producers would need fewer field hands, and there would be less work for tractor operators, cork makers and bottle makers. In the worst case, he added, it could force Champagne producers to consider ripping out vines.

On Friday, France’s finance minister, Eric Lombard, called the trade war “idiotic” and said he would travel to Washington soon. “We need to talk to the Americans to bring the tension back down,” he told French television.

France’s biggest Champagne houses have stayed conspicuously silent, declining to say anything while waiting to see how Mr. Trump’s threat would play out — and whether European officials could get him to back off.

Among them was LVMH Moët Hennessy Louis Vuitton, which sells nearly 35 percent of its wines and spirits in the United States. The company did not respond to a request for comment.

Outside of LVMH’s Moët & Chandon mansion on the Avenue de Champagne, a group of Americans snapped selfies in front of a statue of Dom Pérignon, the monk who invented Champagne. Inside the stately building, no staff members wanted to talk tariffs.

Even so, locals whispered rumors that the big houses were upset by the tariff threat, but expected that it could quite possibly blow over.

After all, some said, Bernard Arnault, France’s richest man and the head of the LVMH empire, which dominates much of Champagne’s production, has a longstanding relationship with the U.S. president and was invited by Mr. Trump to his inauguration. Perhaps Mr. Arnault’s friendship would prevail at the end of the day, they said.

But for now, that is all just speculation. The reality is that nothing is certain — and uncertainty is bad for business.

Back at the Michel Gonet Champagne house, Mr. Boucher pointed to a display of cuvées that were popular among customers in the United States.

“It’s just a stressful situation because we don’t know if the tariffs will even happen,” he said. “It’s not good for anybody.”

Aurelien Breeden and Ségolène Le Stradic contributed reporting.