NEW YORK — Wall Street keeps shaking. After jumping to a big early gain on an encouraging inflation update, the U.S. stock market gave back much of it after other countries announced their retaliations following President Donald Trump’s latest escalation in his trade war.

The S&P 500 was up 0.1% in morning trading after losing nearly all of an initial leap of 1.3%. The unsettled trading comes a day after the index briefly fell more than 10% below its all-time high set last month.

The Dow Jones Industrial Average swung between a gain of 287 points and a loss of 343. It was down 301 points, or 0.7%, as of 10:55 a.m. Eastern time, while the Nasdaq composite was 0.8% higher.

Inflation Report Shows Prices Rose Less

The inflation report, which showed overall prices rose less for U.S. consumers last month than expected, helped companies in the artificial-intelligence industry lead the way on Wall Street. It’s a bounce back after AI stocks got crushed by worries their prices had gone too stratospheric in the market’s run to record after record in recent years.

Nvidia climbed 5.9% to trim its loss for the year so far to 14.2%. Server-maker Super Micro Computer rallied 5.7%, and GE Vernova, which is helping to power AI data centers, rose 4.7%.

Elon Musk’s Tesla, whose price had more than halved since mid-December, was heading toward its first back-to-back gain in a month. It added 7.2%.

But on the losing end of Wall Street were U.S. companies that could be set to feel pain because of Trump’s trade war. Brown-Forman, the company behind Jack Daniel’s whiskey, fell 6.8%, and Harley-Davidson sank 4.6%.

U.S. bourbon and motorcycles are just two of the products the European Union is targeting with its own tariffs announced Wednesday. The moves were in response to Trump’s 25% tariffs on steel and aluminum, which kicked in earlier in the day.

“We deeply regret this measure,” said European Union President Ursula von der Leyen. “Tariffs are taxes. They are bad for business, and worse for consumers.”

Wall Street Is Worried About Tariffs

The question hanging over Wall Street is how much pain Trump will let the economy endure through tariffs and other policies in order to get what he wants. He’s said he wants manufacturing jobs back in the United States, along with a smaller U.S. government workforce, more deportations and other things.

Even if Trump ultimately goes with milder tariffs than feared, damage could still be done. The dizzying barrage of on -again- off -again announcements on tariffs has already begun sapping confidence among U.S. consumers and businesses by ramping up uncertainty. That in itself could cause U.S. households and businesses to pull back on spending, which would hurt the economy.

On Tuesday, for example, Trump said he would double tariffs announced on Canadian steel and aluminum, only to walk it back later in the day after a Canadian province pledged to drop a retaliatory measure that had incensed Trump.

Several U.S. businesses have said they’ve already begun seeing a change in behavior among their customers.

Delta Air Lines Drops While Casey’s General Stores Rise

Delta Air Lines sank 4.9% for one of the market’s sharpest losses to compound its drop of 7.3% from the prior day, when the carrier said it’s seeing demand weaken for close-in bookings for its flights.

Casey’s General Stores, the Ankeny, Iowa-based company that runs nearly 2,900 convenience stores in 20 states, offered some more encouragement. It reported stronger profit and revenue for the latest quarter than analysts expected thanks in part to strength for sales of hot sandwiches and fuel. It also kept steady its forecast for upcoming revenue this year.

Casey’s stock rose 3.5%.

In stock markets abroad, indexes rose across much of Europe after a mixed session in Asia.

In the bond market, Treasury yields edged up to regain more of their losses from recent months sparked by worries about the U.S. economy’s strength. The 10-year Treasury rose to 4.29% from 4.28% late Tuesday and from 4.16% at the start of last week.

Wednesday’s inflation report gave some encouragement when worries are high that Trump’s tariffs could drive prices even higher for U.S. households after U.S. importers pass on the costs to their customers.

It’s also good news for the Federal Reserve, which had been cutting interest rates last year to boost the economy before pausing this year.

Worries had been rising about a worst-case scenario for the economy and for the Fed, one where growth was stagnating but inflation remained high. The Fed has no good tool to fix such “stagflation” because lower interest rates can push inflation higher.