As a powerful blizzard batters the Northeast of the U.S., investors should also prepare to take cover as dark clouds gather over markets.

The tariff uncertainty that plagued stocks this time last year has returned after the Supreme Court struck down levies that President Donald Trump imposed under the International Emergency Economic Powers Act. The stock market’s initial joy Friday may end up being short-lived after Trump responded to the legal blow by announcing a new 15% global tariff on Saturday—up from 10% the day before.

Those two developments reduce the increase in the tariff rate since the start of 2025 to 9 percentage points, down from 10, Goldman Sachs analysts estimated Sunday. 

Following the uncertainty after Trump’s so-called Liberation Day, investors had learned to live with the relative inevitability of Trump’s tariff policy. But that’s all been turned on its head. The new tariffs can only be in place for 150 days—ensuring further twists ahead.

In the more immediate future, Trump’s State of the Union address Tuesday is the perfect opportunity for the president to respond—markets will be watching closely.

There are more storm clouds gathering. The U.S. and Iran remain at loggerheads and a fresh round of talks Thursday could make or break a nuclear deal that would avoid escalation.

If that were not enough for investors to keep track of, Nvidia reports earnings Wednesday at a time of heightened nervousness around the AI trade. The chip maker’s results once determined just how much of a boost other AI stocks would enjoy.

The mood is different these days, though. It’s more about the winners and losers, while the stock market is quick to punish any misstep. That puts pressure on Nvidia to again post market-busting earnings—and heaps expectation on pretty much every other major player in the AI ecosystem.

If the world’s most valuable company disappoints the market, investors really will need to batten down the hatches.

—Callum Keown

Barron’s Live: Emerging market stocks had a banner year in 2025, and there is no letup in sight. What’s behind the strong comeback, how long can the rally last, and which markets and stocks look most attractive now? Join Barron’s senior managing editor Lauren R. Rublin and Editor in Chief Ben Levisohn today at noon when they interview Louis Lau, a member of the Emerging Markets Investment Committee at Brandes Investment Partners, and co-manager of the Brandes Emerging Markets Value Fund. Sign up here.

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Senior administration officials were out defending President Donald Trump’s latest tariff moves after the Supreme Court struck down the levies he imposed using emergency powers. U.S. Trade Representative Jamieson Greer said the Court’s decision wouldn’t invalidate deals the U.S. has already struck. Leaders abroad are considering next steps.

• Germany’s Bernd Lange, a member of the European Parliament and chairman of its trade committee, proposed to suspend work on approving the U.S.-EU trade deal amid “pure customs chaos.” He wants commitments from the U.S., though questioned whether Trump’s latest tariffs represent a breach of the Turnberry Agreement.

• Greer says the decision shouldn’t affect the U.S.-China trade framework, brushing aside concerns China could renege on promises to buy American soybeans, among other agreements. He told Fox News Sunday that trade deals weren’t premised on the case’s outcome and that they could pivot to other tools.

• Almost immediately after the Supreme Court released its decision, Trump imposed 10% tariffs on imports using another authority that gives him 150 days to craft a more permanent solution. Trump raised that to 15% on Saturday. Greer told ABC’s This Week that they found ways to reconstruct the trade strategy.

• Treasury Secretary Scott Bessent wouldn’t discuss refunding the approximately $130 billion in tariffs collected since last year under the emergency order, telling CNN it’s up to the courts to decide. Administration officials previously argued that the complexities of refunds gave them confidence they would prevail in the case.

What’s Next: Trump’s approval rating has slipped, with 64% of respondents to an ABC News, Ipsos, Washington Post poll saying they disapproved of his handling of tariffs. Trade will likely feature prominently in Trump’s State of the Union address on Tuesday.

—Liz Moyer

White House National Economic Council Director Kevin Hassett has apologized for his sharp criticism of a research paper that contradicted the White House’s messaging around tariffs. In a statement posted to economist Laurence Kotlikoff’s Substack, Hassett said he regretted his choice of words.

• The paper in question was published by the Federal Reserve Bank of New York on Tuesday, and found that U.S. businesses and consumers have shouldered the vast share of the economic burden posed by higher tariffs over the past year.

• Hassett lambasted both the paper and its authors a day later, calling it the “worst paper” he’s ever seen in the history of the Federal Reserve system during an appearance on CNBC’s Squawk Box. He also called for the people associated with the paper to be disciplined.

• “I regret suggesting the authors should be disciplined for their research. Indeed, I retract that suggestion,” Hassett’s statement read, adding the Fed’s independence extends to its research. “I was upset at what I felt and feel was the Fed’s dissemination of politically sensitive research on an issue that goes beyond its primary focus.”

What’s Next: Looking forward, Hassett used an appearance on Fox Business to urge the Fed to focus on monetary policy and to avoid going “willy-nilly into every single political topic if they want to preserve their political independence.”

—Sabrina Escobar and Megan Leonhardt

Whether Netflix or Paramount Skydance wins the takeover battle for Warner Bros. Discovery, the winning suitor will likely overpay and take on billions in debt, Barron’s Andrew Bary reports. Warner Bros. gave Paramount until today to improve its $30-a-share offer, but said Netflix retains “matching rights.”

• Netflix reached a deal in December to buy Warner’s HBO, movie studio, TV production, and streaming-related assets for $27.75 a share in cash, or $82.7 billion, including assumed debt. Warner’s cable TV properties, including CNN, Discovery, and Turner Networks, would be spun off to Warner shareholders.

• Paramount’s offer is for $108 billion plus an additional payment if the deal doesn’t close by the end of 2026. Paramount has offered to buy the whole company, versus Netflix’s plan, and insists its offer is superior. 

• LightShed Partners analyst Rich Greenfield said Paramount and CEO David Ellison “should walk away now,” and potentially buy Warner’s assets more cheaply later. Greenfield’s view is that Warner’s cable assets—if not the entire company—could become available if a Netflix/Warner deal is blocked on antitrust grounds.

• President Trump has also put pressure on the deal, demanding Netflix oust board member Susan Rice, a former Clinton, Obama, and Biden administration official, “or pay the consequences.” His post linked to a post by ally Laura Loomer, who said Trump should terminate the deal now.

What’s Next: Warner said Paramount indicated it was prepared to pay $31 a share, which “wasn’t Paramount’s best and final” offer. That prompted speculation that Paramount might go to $32 to $33 a share—or higher. Netflix Co-CEO Ted Sarandos said it may be prepared to match any Paramount bid.

—Andrew Bary and Janet H. Cho

Memory-chip makers are the latest winners in the AI trade. Micron Technology, SK Hynix, and Samsung Electronics are soaring as AI growth creates huge demand for their hardware. But investors beware: The race to increase production risks creating an eventual glut of hardware and a painful crash.

• Micron reports February-quarter earnings next month. Revenue is projected to more than double from a year ago and earnings are forecast to rise fivefold. Micron has pledged roughly $200 billion to expand its U.S. facilities. In mid-2027, Micron begins wafer output from a $50 billion facilities expansion in Idaho.

• AI servers need high-bandwidth memory, or HBM, to support the processing of huge amounts of data. HBM is a specialized form of dynamic random-access memory, or DRAM, with other variants also required. At the same time, the latest AI servers also require NAND flash memory to store large data sets.

• Because HBM is resource-intensive—each unit needs roughly three times the semiconductor wafer capacity of standard memory—expanding supply reduces production of other memory types and drives prices higher across the sector. TrendForce projects the memory market will reach $551.6 billion in 2026 and $842.7 billion in 2027.

• Pricing suggests demand is far outpacing supply. UBS expects contract pricing for a common DRAM type to rise 62% in the first quarter 2026 from the previous quarter, with NAND prices increasing about 40%. These costs pressure device makers such as Apple, but there is little evidence of weakening demand.

What’s Next: Supply constraints appear likely for the next 12-18 months. SK Hynix’s Yongin cluster should reach volume production in late 2027, with additions in 2028 and Micron’s $100 billion New York project in 2030. Intel and Japan’s SoftBank are developing new memory technology but it won’t be commercialized until 2030.

—Adam Clark

Airlines canceled thousands of flights because of a winter storm barreling up the East Coast, but that’s not the only thing spreading chaos across the air travel industry. Amid the ongoing government shutdown, the Department of Homeland Security threatened to restrict some airport screening operations before reversing course.